String
A String object is used to manipulate a series of characters.
A String object is created with new String() or by assigning a string to a variable.
var s = new String("Hello world!");
// or just:
var s = "Hello world!";
// Finding the length of a string
var message = "Hello World!";
var x = message.length; // x is 12
// Converting a string to uppercase
var message="Hello world!";
var x=message.toUpperCase(); // x is "HELLO WORLD!"
/* The indexOf()method returns the position (as a number) of the
first found occurrence of a specified text inside a string */
var str="Hello world, welcome to OpenAir.";
var n=str.indexOf("welcome");
String Properties
Property |
Description |
---|---|
constructor |
Returns the function that created the String object's prototype. |
length |
Returns the length of a string. |
prototype |
Allows you to add properties and methods to a String object. |
String Methods
Method |
Description |
---|---|
charAt() |
Returns the character at the specified index. |
charCodeAt() |
Returns the Unicode of the character at the specified index. |
concat() |
Joins two or more strings, and returns a copy of the joined strings. |
fromCharCode() |
Converts Unicode values to characters. |
indexOf() |
Returns the position of the first found occurrence of a specified value in a string. |
lastIndexOf() |
Returns the position of the last found occurrence of a specified value in a string. |
match() |
Searches for a match between a regular expression and a string, and returns the matches. |
replace() |
Searches for a match between a substring (or regular expression) and a string, and replaces the matched substring with a new substring. |
search() |
Searches for a match between a regular expression and a string, and returns the position of the match. |
slice() |
Extracts a part of a string and returns a new string. |
split() |
Splits a string into an array of substrings. |
substr() |
Extracts the characters from a string, beginning at a specified start position, and through the specified number of character. |
substring() |
Extracts the characters from a string, between two specified indices. |
toLowerCase() |
Converts a string to lowercase letters. |
toUpperCase() |
Converts a string to uppercase letters. |
trim() |
Removes white space from both ends of a string. |
valueOf() |
Returns the primitive value of a String object. |