Detailed explanation and examples of PHP switch statement

Detailed explanation and examples of PHP switch statement

In PHP programming, the switch statement is a conditional statement used to perform multiple different operations. It is similar to an if statement, but is suitable for situations where only one variable needs to be compared with several different values.

Grammar form

The usual grammatical form of the switch statement is as follows:

switch (expression) {
    case value1:
        // code to be executed if expression matches value1
        break;
    case value2:
        // code to be executed if expression matches value2
        break;
    // add more cases as needed
    default:
        // code to be executed if expression does not match any cases
}

• expression represents the variable or expression to be compared.
• case value: defines the execution code block for each matching value.
• break is used to terminate the execution of the switch statement and jump out of the switch block.
• default is optional and is used to specify the default code block to be executed when expression does not match any case.

Example

Let us illustrate the use of switch statement through a simple example:

$day = "Monday";

switch ($day) {
    case "Monday":
        echo "Today is Monday";
        break;
    case "Tuesday":
        echo "Today is Tuesday";
        break;
    case "Wednesday":
        echo "Today is Wednesday";
        break;
    case "Thursday":
        echo "Today is Thursday";
        break;
    case "Friday":
        echo "Today is Friday";
        break;
    case "Saturday":
        echo "Today is Saturday";
        break;
    case "Sunday":
        echo "Today is Sunday";
        break;
    default:
        echo "Incorrect input, please re-enter";
}

In this example, according to different $day values, the program will output the corresponding day of the week. If the $day value is not among the predefined days of the week, "Incorrect input, please re-enter" will be output.

Notes

• break must be added at the end of each case, otherwise the next case will continue to be executed. The
• default block is optional, but is generally recommended to include to handle unexpected values.
• expression must return a value, and the value in each case must match the value of expression before the corresponding code block will be executed.

In short, the switch statement is a useful tool for comparing multiple values ​​of the same variable. By rationally using switch statements, the code can be greatly simplified and readability and maintainability improved.

I hope this article can help you better understand the usage and precautions of switch statements in PHP.

The above is the detailed content of Detailed explanation and examples of PHP switch statement. For more information, please follow other related articles on the PHP Chinese website!