if
[aliased]
aliases: C language:Control keywords:if [primary] | C language:Control keywords:else | Else | else | If
From clc-wiki
Description
Conditionally execute a statement or one of two statements.
Details
if (expression) statement;
Will evaluate the scalar expression in parentheses and if it compares not equal to zero will execute the statement.
if (expression) statement1; else statement2;
Will execute statement1
if expression
compares not equal to zero. Will instead execute statement2
if expression
compares equal to zero.
Either or both statements can be a compound statement.
Examples
#include <stdio.h> #include <stdlib.h> #include <string.h> int main(int argc, char *argv[]) { if (argc < 1) { puts("I don't even know my own name!"); return EXIT_FAILURE; } if (strcmp(argv[0],"what_am_i_called") != 0) puts("If renamed, this program will print its name"); else printf("My name is %s",argv[0]); return EXIT_SUCCESS; }
Grammar
<c_grammar>selection-statement:
if ( expression ) statement if ( expression ) statement else statement switch ( expression ) statement
</c_grammar>
References
- ISO C99 Standard, 3.8.4.1