The meaning and usage of the default keyword in C language

The default keyword is used in a switch statement, indicating the default code block executed when there is no matching case branch. It must be placed at the end and will only be executed if the expression value does not match any case branch. This branch is optional, and no code will be executed if there is no.

default keywords in C language

meaning

The default keyword is used in the switch statement, which represents the default code block executed when there is no matching case branch.

usage

grammar:

 <code class="c">switch(expression) { case value1: // 代码块case value2: // 代码块... default: // 默认代码块}</code>

When using the default keyword, you need to pay attention to the following points:

• The default branch must be placed at the end of the switch statement.
• The default branch is executed only if no other case branches match the value of expression.
• The default branch is optional, and if there is no default branch, no code is executed when the value of expression does not match any case branch.

Example

The following example demonstrates the usage of the default keyword:

 <code class="c">#include <stdio.h> int main() { int grade = 80; switch (grade) { case 90: printf("A"); break; case 80: printf("B"); break; case 70: printf("C"); break; default: printf("F"); break; } return 0; }</stdio.h></code>

In this example, if the grade is equal to 90, 80, or 70, the corresponding letter level is printed. If grade does not equal these values, the default letter level F is printed.

in conclusion

The default keyword provides a way for switch statements to handle all other cases that may not match any case branch. It can be used to ensure that certain code is executed regardless of the value of the expression.

The above is the detailed content of The meaning and usage of the default keyword in C language. For more information, please follow other related articles on the PHP Chinese website!