C language default: a tool for handling unmatched situations

The default in C language is an optional part of the switch statement, which is used to handle unmatched situations, provides bottom-up processing and simplifies code. Syntax: switch (expression) { case constant1: statement1; break; case constant2: statement2; break; default: default_statement; break; } Function: (1) When the value of expression does not match any case constant, execute the default part. (2) If sw

C language default: a tool to deal with unmatched situations

In C, default is an optional part of the switch statement, and it will be executed when no other case matches. It is usually used to handle unspecified input or exceptions.

grammar

 <code class="c">switch (expression) { case constant1: statement1; break; case constant2: statement2; break; default: default_statement; break; }</code>

effect

• Handle unmatched cases: When the value of expression does not match any case constant, execute the default part.
• Provides a bottom-up processing: If switch statement does not cover all possible situations, default can ensure that there is a bottom-up processing mechanism.
• Simplified code: Simplified switch statements by concentrating common or exceptional handling into default .

Example

 <code class="c">int number = 10; switch (number) { case 1: printf("One\n"); break; case 2: printf("Two\n"); break; default: printf("Number not found\n"); }</code>

Output:

 <code>Number not found</code>

Notice :

• default must be placed at the end of switch statement.
• default can also have its own break statement, although it is not required.
• If there is no default and there is no case match, switch statement will execute all case parts.

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