C语言 if嵌套

在C编程中，嵌套if-else语句始终是合法的，这意味着您可以在另一个if或else if语句中使用一个if或else if语句。

嵌套 if - 语法

嵌套if语句的语法如下所示:

if( boolean_expression 1) {

   /* Executes when the boolean expression 1 is true */
   if(boolean_expression 2) {
      /* Executes when the boolean expression 2 is true */
   }
}

您可以使用与嵌套if语句类似的方式嵌套else if.else。

嵌套 if - 示例

#include <stdio.h>

int main () {

   /* local variable definition */
   int a = 100;
   int b = 200;

   /* check the boolean condition */
   if( a == 100 ) {

      /* if condition is true then check the following */
      if( b == 200 ) {
         /* if condition is true then print the following */
         printf("Value of a is 100 and b is 200\n" );
      }
   }

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

   return 0;
}

编译并执行上述代码后，将产生以下结果:

Value of a is 100 and b is 200
Exact value of a is : 100

Exact value of b is : 200