Usage of default in c language

The default keyword in C language is an optional statement, used when there is no matching case statement in the switch-case statement. It provides default behavior that ensures that the switch-case statement performs some operation even if there is no matching case.

Usage of default in C language

default keyword

In the switch-case statement of C language, default is an optional statement, used to handle the situation where there is no matching case statement. When executing switch-case, if the value of the control variable does not match any case condition, the default statement block is executed.

Syntax

<code class="c">switch (expression) {
    case value1:
        // Code to be executed for value1
        break;
    case value2:
        // Code to be executed for value2
        break;
    ...
    default:
        // Code to be executed if no case matches
        break;
}</code>

Function

• Provides default behavior to ensure that even if there is no matching case, switch-case Statements can also perform some operations.
  *Prevent programs from undefined behavior or unexpected termination.
• Simplify the code and avoid using multiple if-else statements to handle different situations.

Note:

• The default statement must be placed at the end of the switch-case statement because it matches all other cases.
• The default statement can contain one or more statements, enclosed in curly braces ({}).
• If there is no default statement and the expression does not match any case, no action will be performed.
• If the expression is an integer or enumeration type, you can omit the default statement, and the program will automatically perform the "implicit" default behavior, that is, do nothing.
• However, for other types, such as strings or structures, the default statement must be explicitly specified, otherwise an error will occur in the program.

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