13.22 Number Class

The Number class handles limited-precision signed base 10 numbers. A Number guarantees 38 decimal digits of precision. All positive numbers in the range displayed here can be represented to a full 38-digit precision:

10^-130

and

9.99999999999999999999999999999999999999*10^125 

The range of representable negative numbers is symmetrical.

The number zero can be represented exactly. Also, Oracle numbers have representations for positive and negative infinity. These are generally used to indicate overflow.

The internal storage type is opaque and private. Scale is not preserved when Number instances are created.

Number does not support the concept of NaN and is not IEEE-754-85 compliant. Number does support +Infinity and -Infinity.

Objects from the Number class can be used as standalone class objects in client side numeric computations. They can also be used to fetch from and set to the database.

Example 13-10 How to Retrieve and Use a Number Object

This example demonstrates a Number column value being retrieved from the database, a bind using a Number object, and a comparison using a standalone Number object.

/* Create a connection */
Environment *env = Environment::createEnvironment(Environment::DEFAULT);
Connection *conn = Connection(user, passwd, db);

/* Create a statement and associate a select clause with it */
string sqlStmt = "SELECT department_id FROM DEPARTMENTS";
Statement *stmt = conn->createStatement(sqlStmt);

/* Run the statement to get a result set */
ResultSet *rset = stmt->executeQuery();
while(rset->next())
{
   Number deptId = rset->getNumber(1);
   /* Display the department id with the format string 9,999 */
   cout << "Department Id" << deptId.toText(env, "9,999");

   /* Use the number obtained as a bind value in the following query */
   stmt->setSQL("SELECT * FROM EMPLOYEES WHERE department_id = :x");
   stmt->setNumber(1, deptId);
   ResultSet *rset2 = stmt->executeQuery();
   .
   .
}
/* Using a Number object as a standalone and the operations on them */

/* Create a number to a double value */
double value = 2345.123;
Number nu1 (value);

/* Some common Number methods */
Number abs = nu1.abs();    /* absolute value */
Number sqrt = nu1.squareroot();    /* square root */
Environment *env = Environment::createEnvironment();

//create a null year-month interval
IntervalYM ym
if(ym.isNull())
   cout << "\n ym is null";

//assign a non null value to ym
IntervalYM anotherYM(env, "10-30");
ym = anotherYM;

//now all operations are valid on ym
int yr = ym.getYear();

Table 13-30 Summary of Number Methods

Method Summary

Number()

Number class constructor.

abs()

Returns the absolute value of the number.

arcCos()

Returns the arcCosine of the number.

arcSin()

Returns the arcSine of the number.

arcTan()

Returns the arcTangent of the number.

arcTan2()

Returns the arcTangent2 of the input number y and this number x.

ceil()

Returns the smallest integral value not less than the value of the number.

cos()

Returns the cosine of the number.

exp()

Returns the natural exponent of the number.

floor()

Returns the largest integral value not greater than the value of the number.

fromBytes()

Returns a Number derived from a Bytes object.

fromText()

Returns a Number from a given number string, format string and NLS parameters specified.

hypCos()

Returns the hyperbolic cosine of the number.

hypSin()

Returns the hyperbolic sine of the number.

hypTan()

Returns the hyperbolic tangent of the number.

intPower()

Returns the number raised to the integer value specified.

isNull()

Checks if Number is NULL.

ln()

Returns the natural logarithm of the number.

log()

Returns the logarithm of the number to the base value specified.

operator++()

Increments the number.

operator--()

Decrements the number.

operator*()

Returns the product of two Numbers.

operator/()

Returns the quotient of two Numbers.

operator%()

Returns the modulo of two Numbers.

operator+()

Returns the sum of two Numbers.

operator-()

Returns the negated value of Number.

operator-()

Returns the difference between two Numbers.

operator<()

Checks if a number is less than an other number.

operator<=()

Checks if a number is less than or equal to an other number.

operator>()

Checks if a number is greater than an other number.

operator>=()

Checks if a number is greater than or equal to an other number.

operator=()

Assigns one number to another.

operator==()

Checks if two numbers are equal.

operator!=()

Checks if two numbers are not equal.

operator*=()

Multiplication assignment.

operator/=()

Division assignment.

operator%=()

Modulo assignment.

operator+=()

Addition assignment.

operator-=()

Subtraction assignment.

operator char()

Returns Number converted to native char.

operator signed char()

Returns Number converted to native signed char.

operator double()

Returns Number converted to a native double.

operator float()

Returns Number converted to a native float.

operator int()

Returns Number converted to native integer.

operator long()

Returns Number converted to native long.

operator long double()

Returns Number converted to a native long double.

operator short()

Returns Number converted to native short integer.

operator unsigned char()

Returns Number converted to an unsigned native char.

operator unsigned int()

Returns Number converted to an unsigned native integer.

operator unsigned long()

Returns Number converted to an unsigned native long.

operator unsigned short()

Returns Number converted to an unsigned native short integer.

power()

Returns Number raised to the power of another number specified.

prec()

Returns Number rounded to digits of precision specified.

round()

Returns Number rounded to decimal place specified. Negative values are allowed.

setNull()

Sets Number to NULL.

shift()

Returns a Number that is equivalent to the passed value * 10^n, where n may be positive or negative.

sign()

Returns the sign of the value of the passed value: -1 for the passed value < 0, 0 for the passed value == 0, and 1 for the passed value > 0.

sin()

Returns sine of the number.

squareroot()

Returns the square root of the number.

tan()

Returns tangent of the number.

toBytes()

Returns a Bytes object representing the Number.

toText()

Returns the number as a string formatted based on the format and NLS parameters.

trunc()

Returns a Number with the value truncated at n decimal place(s). Negative values are allowed.

13.22.1 Number()

Number class constructor.

Syntax Description
Number();

Default constructor.

Number(
   const Number &srcNum);

Creates a copy of a Number.

Number(
   long double &val);

Translates a native long double into a Number. The Number is created using the precision of the platform-specific constant LDBL_DIG.

Number(
   double val);

Translates a native double into a Number. The Number is created using the precision of the platform-specific constant DBL_DIG.

Number(
   float val);

Translates a native float into a Number. The Number is created using the precision of the platform-specific constant FLT_DIG.

Number(
   long val);

Translates a native long into a Number.

Number(
   int val);

Translates a native int into a Number.

Number(
   shot val);

Translates a native short into a Number.

Number(
   char val);

Translates a native char into a Number.

Number(
   signed char val);

Translates a native signed char into a Number.

Number(
   unsigned long val);

Translates an native unsigned long into a Number.

Number(
   unsigned int val);

Translates a native unsigned int into a Number.

Number(
   unsigned short val);

Translates a native unsigned short into a Number.

Number(
   unsigned char val);

Translates the unsigned character array into a Number.

Parameter Description
srcNum

The source Number copied into the new Number object.

val

The value assigned to the Number object.

13.22.2 abs()

This method returns the absolute value of the Number object.

Syntax

const Number abs() const;

13.22.3 arcCos()

This method returns the arccosine of the Number object.

Syntax

const Number arcCos() const;

13.22.4 arcSin()

This method returns the arcsine of the Number object.

Syntax

const Number arcSin() const;

13.22.5 arcTan()

This method returns the arctangent of the Number object.

Syntax

const Number arcTan() const;

13.22.6 arcTan2()

This method returns the arctangent of the Number object with the parameter specified. It returns atan2 (val, x) where val is the parameter specified and x is the current number object.

Syntax

const Number arcTan2(
   const Number &val) const;
Parameter Description
val

Number parameter val to the arcTangent function atan2(val,x).

13.22.7 ceil()

This method returns the smallest integer that is greater than or equal to the Number object.

Syntax

const Number ceil() const;

13.22.8 cos()

This method returns the cosine of the Number object.

Syntax

const Number cos() const;

13.22.9 exp()

This method returns the natural exponential of the Number object.

Syntax

const Number exp() const;

13.22.10 floor()

This method returns the largest integer that is less than or equal to the Number object.

Syntax

const Number floor() const;

13.22.11 fromBytes()

This method returns a Number object represented by the byte string specified.

Syntax

void fromBytes(
   const Bytes &str);
Parameter Description
str

A byte string.

13.22.12 fromText()

Sets Number object to value represented by a string or UString.

The value is interpreted based on the fmt and nlsParam parameters. In cases where nlsParam is not passed, the Globalization Support settings of the envp parameter are used.

See Also:

Oracle Database SQL Language Reference for information on TO_NUMBER

Syntax Description
void fromText(
   const Environment *envp,
   const string &number,
   const string &fmt,
   const string &nlsParam = "");

Sets Number object to value represented by a string.

void fromText(
   const Environment *envp,
   const UString &number,
   const UString &fmt,
   const UString &nlsParam);

Sets Number object to value represented by a UString.

Parameter Description
envp

The OCCI environment.

number

The number string to be converted to a Number object.

fmt

The format string.

nlsParam

The NLS parameters string. If nlsParam is specified, this determines the NLS parameters to be used for the conversion. If nlsParam is not specified, the NLS parameters are picked up from envp.

13.22.13 hypCos()

This method returns the hypercosine of the Number object.

Syntax

const Number hypCos() const;

13.22.14 hypSin()

This method returns the hypersine of the Number object.

Syntax

const Number hypSin() const;

13.22.15 hypTan()

This method returns the hypertangent of the Number object.

Syntax

const Number hypTan() const;

13.22.16 intPower()

This method returns a Number whose value is the number object raised to the power of the value specified.

Syntax

const Number intPower(
   int val) const;
Parameter Description
val

Power to which the number is raised.

13.22.17 isNull()

This method tests whether the Number object is NULL. If the Number object is NULL, then TRUE is returned; otherwise, FALSE is returned.

Syntax

bool isNull() const;

13.22.18 ln()

This method returns the natural logarithm of the Number object.

Syntax

const Number ln() const;

13.22.19 log()

This method returns the logarithm of the Number object with the base provided by the parameter specified.

Syntax

const Number log(
   const Number &val) const;
Parameter Description
val

The base to be used in the logarithm calculation.

13.22.20 operator++()

Unary operator++(). This is a postfix operator.

Syntax Description
Number& operator++();

This method returns the Number object incremented by 1.

const Number operator++(
   int incr);

This method returns the Number object incremented by the integer specified.

Parameter Description
incr

The number by which the Number object is incremented.

13.22.21 operator--()

Unary operator--(). This is a prefix operator.

Syntax Description
Number& operator--();

This method returns the Number object decremented by 1.

const Number operator--(
   int decr);

This method returns the Number object decremented by the integer specified.

Parameter Description
decr

The number by which the Number object is decremented.

13.22.22 operator*()

This method returns the product of the parameters specified.

Syntax

Number operator*(
   const Number &first,
   const Number &second);
Parameter Description
first

First multiplicand.

second

Second multiplicand.

13.22.23 operator/()

This method returns the quotient of the parameters specified.

Syntax

Number operator/(
   const Number &dividend,
   const Number &divisor);
Parameter Description
dividend

The number to be divided.

divisor

The number by which to divide.

13.22.24 operator%()

This method returns the remainder of the division of the parameters specified.

Syntax

Number operator%(
   const Number &dividend,
   const Number &divider);
Parameter Description
dividend

The number to be divided.

divizor

The number by which to divide.

13.22.25 operator+()

This method returns the sum of the parameters specified.

Syntax

Number operator+(
   const Number &first,
   const Number &second);
Parameter Description
first

First number to be added.

second

Second number to be added.

13.22.26 operator-()

Unary operator-(). This method returns the negated value of the Number object.

Syntax

const Number operator-();

13.22.27 operator-()

This method returns the difference between the parameters specified.

Syntax

Number operator-(
   const Number &subtrahend,
   const Number &subtractor);
Parameter Description
subtrahend

The number to be reduced.

subtractor

The number to be subtracted.

13.22.28 operator<()

This method checks whether the first parameter specified is less than the second parameter specified. If the first parameter is less than the second parameter, then TRUE is returned; otherwise, FALSE is returned. If either parameter equals infinity, then FALSE is returned.

Syntax

bool operator<(
   const Number &first,
   const Number &second);
Parameter Description
first

First number to be compared.

second

Second number to be compared.

13.22.29 operator<=()

This method checks whether the first parameter specified is less than or equal to the second parameter specified. If the first parameter is less than or equal to the second parameter, then TRUE is returned; otherwise, FALSE is returned. If either parameter equals infinity, then FALSE is returned.

Syntax

bool operator<=(
   const Number &first,
   const Number &second);
Parameter Description
first

First number to be compared.

second

Second number to be compared.

13.22.30 operator>()

This method checks whether the first parameter specified is greater than the second parameter specified. If the first parameter is greater than the second parameter, then TRUE is returned; otherwise, FALSE is returned. If either parameter equals infinity, then FALSE is returned.

Syntax

bool operator>(
   const Number &first,
   const Number &second);
Parameter Description
first

First number to be compared.

second

Second number to be compared.

13.22.31 operator>=()

This method checks whether the first parameter specified is greater than or equal to the second parameter specified. If the first parameter is greater than or equal to the second parameter, then TRUE is returned; otherwise, FALSE is returned. If either parameter equals infinity, then FALSE is returned.

Syntax

bool operator>=(
   const Number &first,
   const Number &second);
Parameter Description
first

First number to be compared.

second

Second number to be compared.

13.22.32 operator==()

This method checks whether the parameters specified are equal. If the parameters are equal, then TRUE is returned; otherwise, FALSE is returned. If either parameter equals +infinity or -infinity, then FALSE is returned.

Syntax

bool operator==(
   const Number &first,
   const Number &second);
Parameter Description
first

First number to be compared.

second

Second number to be compared.

13.22.33 operator!=()

This method checks whether the first parameter specified equals the second parameter specified. If the parameters are not equal, TRUE is returned; otherwise, FALSE is returned.

Syntax

bool operator!=(
   const Number &first,
   const Number &second);
Parameter Description
first

First number to be compared.

second

Second number to be compared.

13.22.34 operator=()

This method assigns the value of the parameter specified to the Number object.

Syntax

Number& operator=(
   const Number &num);
Parameter Description
num

A parameter of type Number.

13.22.35 operator*=()

This method multiplies the Number object by the parameter specified, and assigns the product to the Number object.

Syntax

Number& operator*=(
   const Number &num);
Parameter Description
num

A parameter of type Number.

13.22.36 operator/=()

This method divides the Number object by the parameter specified, and assigns the quotient to the Number object.

Syntax

Number& operator/=(
   const Number &num);
Parameter Description
num

A parameter of type Number.

13.22.37 operator%=()

This method divides the Number object by the parameter specified, and assigns the remainder to the Number object.

Syntax

Number& operator%=(
   const Number &num);
Parameter Description
num

A parameter of type Number.

13.22.38 operator+=()

This method adds the Number object and the parameter specified, and assigns the sum to the Number object.

Syntax

Number& operator+=(
   const Number &num);
Parameter Description
num

A parameter of type Number.

13.22.39 operator-=()

This method subtracts the parameter specified from the Number object, and assigns the difference to the Number object.

Syntax

Number& operator-=(
   const Number &num);
Parameter Description
num

A parameter of type Number.

13.22.40 operator char()

This method returns the value of the Number object converted to a native char.

Syntax

operator char() const;

13.22.41 operator signed char()

This method returns the value of the Number object converted to a native signed char.

Syntax

operator signed char() const;

13.22.42 operator double()

This method returns the value of the Number object converted to a native double.

Syntax

operator double() const;

13.22.43 operator float()

This method returns the value of the Number object converted to a native float.

Syntax

operator float() const;

13.22.44 operator int()

This method returns the value of the Number object converted to a native int.

Syntax

operator int() const;

13.22.45 operator long()

This method returns the value of the Number object converted to a native long.

Syntax

operator long() const;

13.22.46 operator long double()

This method returns the value of the Number object converted to a native long double.

Syntax

operator long double() const;

13.22.47 operator short()

This method returns the value of the Number object converted to a native short integer.

Syntax

operator short() const;

13.22.48 operator unsigned char()

This method returns the value of the Number object converted to a native unsigned char.

Syntax

operator unsigned char() const;

13.22.49 operator unsigned int()

This method returns the value of the Number object converted to a native unsigned int.

Syntax

operator unsigned int() const;

13.22.50 operator unsigned long()

This method returns the value of the Number object converted to a native unsigned long.

Syntax

operator unsigned long() const;

13.22.51 operator unsigned short()

This method returns the value of the Number object converted to a native unsigned short integer.

Syntax

operator unsigned short() const;

13.22.52 power()

This method returns the value of the Number object raised to the power of the value provided by the parameter specified.

Syntax

const Number power(
   const Number &val) const;
Parameter Description
val

The power to which the number has to be raised.

13.22.53 prec()

This method returns the value of the Number object rounded to the digits of precision provided by the parameter specified.

Syntax

const Number prec(
   int digits) const;
Parameter Description
digits

The number of digits of precision.

13.22.54 round()

This method returns the value of the Number object rounded to the decimal place provided by the parameter specified.

Syntax

const Number round(
   int decPlace) const;
Parameter Description
decPlace

The number of digits to the right of the decimal point.

13.22.55 setNull()

This method sets the value of the Number object to NULL.

Syntax

void setNull();

13.22.56 shift()

This method returns the Number object multiplied by 10 to the power provided by the parameter specified.

Syntax

const Number shift(
   int val) const;
Parameter Description
val

An integer value.

13.22.57 sign()

This method returns the sign of the value of the Number object. If the Number object is negative, then create a Date object using integer parameters is returned. If the Number object equals 0, then create a Date object using integer parameters is returned. If the Number object is positive, then 1 is returned.

Syntax

const int sign() const;

13.22.58 sin()

This method returns the sin of the Number object.

Syntax

const Number sin() const;

13.22.59 squareroot()

This method returns the square root of the Number object.

Syntax

const Number squareroot() const;

13.22.60 tan()

This method returns the tangent of the Number object.

Syntax

const Number tan() const;

13.22.61 toBytes()

This method converts the Number object into a Bytes object. The bytes representation is assumed to be in length excluded format, that is, the Byte.length() method gives the length of valid bytes and the 0th byte is the exponent byte.

Syntax

Bytes toBytes() const;

13.22.62 toText()

Convert the Number object to a formatted string or UString based on the parameters specified.

Syntax Description
string toText(
   const Environment *envp,
   const string &fmt,
   const string &nlsParam = "") const;

Convert the Number object to a formatted string based on the parameters specified.

UString toText(
   const Environment *envp,
   const UString &fmt,
   const UString &nlsParam) const;

Convert the Number object to a UString based on the parameters specified.

Parameter Description
envp

The OCCI environment.

fmt

The format string.

nlsParam

The NLS parameters string. If nlsParam is specified, this determines the NLS parameters to be used for the conversion. If nlsParam is not specified, the NLS parameters are picked up from envp.

13.22.63 trunc()

This method returns the Number object truncated at the number of decimal places provided by the parameter specified.

Syntax

const Number trunc(
   int decPlace) const;
Parameter Description
decPlace

The number of places to the right of the decimal place at which the value is to be truncated.