C语言 if语句

if语句由一个布尔表达式后跟一个或多个语句组成。

if语句 - 语法

C编程语言中‘if’语句的语法是

if(boolean_expression) {
   /* statement(s) will execute if the boolean expression is true */
}

if语句- 流程图

if语句 - 示例

#include <stdio.h>

int main () {

   /* local variable definition */
   int a=10;

   /* check the boolean condition using if statement */

   if( a < 20 ) {
      /* if condition is true then print the following */
      printf("a is less than 20\n" );
   }

   printf("value of a is : %d\n", a);

   return 0;
}

编译并执行上述代码时，将生成以下结果:

a is less than 20;
value of a is : 10