Statements

A statement consists of one or more key words, symbolic names, literal constants, and operators, with appropriate punctuation. In FORTRAN, no keywords are reserved in all contexts. Most statements begin with a keyword; the exceptions are the statement function and assignment statements.

Executable and Nonexecutable Statements

Every statement is either executable or nonexecutable. In general, if a statement specifies an action to be taken at runtime, it is executable. Otherwise, it is nonexecutable.

The nonexecutable statements specify attributes, such as type and size; determine arrangement or order; define initial data values; specify editing instructions; define statement functions; classify program units; and define entry points. In general, nonexecutable statements are completed before execution of the first executable statement.

FORTRAN Statements

Table 1-4 FORTRAN Statements

ACCEPT* ASSIGN* Assignment* AUTOMATIC BACKSPACE* BLOCK DATA BYTE CALL* CHARACTER CLOSE* COMMON COMPLEX CONTINUE* DATA DECODE* DIMENSION DO* DO WHILE*

DOUBLE COMPLEX DOUBLE PRECISION ELSE* ELSE IF* ENCODE* END* END DO* END FILE* END IF* END MAP END STRUCTURE END UNION ENTRY EQUIVALENCE EXTERNAL FORMAT FUNCTION GOTO*

GOTO (Assigned)* GOTO (Unconditional)* IF (Arithmetic)* IF (Block)* IF (Logical)* IMPLICIT INCLUDE INQUIRE* INTEGER INTRINSIC LOGICAL MAP NAMELIST OPEN* OPTIONS PARAMETER PAUSE* POINTER

PRINT* PRAGMA PROGRAM REAL RECORD RETURN* REWIND* SAVE Statement Function STATIC* STOP* STRUCTURE SUBROUTINE TYPE UNION VIRTUAL VOLATILE WRITE*

The asterisk (*) in the table indicates an executable statement.