Tips on using PHP Switch statement: What happens if you don't use Break?

The Switch statement in PHP is a commonly used conditional statement, usually used to execute different code blocks according to different situations. In the Switch statement, each case will be followed by a code block, and the break keyword is usually used at the end of the code block to terminate the execution of the current case and avoid continuing to execute subsequent cases.

However, in some cases, we may encounter situations where the break keyword is not used. What will be the consequences? Next, we illustrate this issue through specific code examples.

First, let us look at a classic Switch statement example, using the break keyword:

$fruit = "apple";

switch ($fruit) {
    case "apple":
        echo "Selected fruit is apple.";
        break;
    case "banana":
        echo "Selected fruit is banana.";
        break;
    case "orange":
        echo "Selected fruit is orange.";
        break;
    default:
        echo "Invalid fruit selection.";
}

In the above code, according to the variable $fruit The value of will execute the corresponding code block, and use break at the end of each case to end the current case execution.

Next, we will modify the same example without using the break keyword:

$fruit = "apple";

switch ($fruit) {
    case "apple":
        echo "Selected fruit is apple.";
    case "banana":
        echo "Selected fruit is banana.";
    case "orange":
        echo "Selected fruit is orange.";
    default:
        echo "Invalid fruit selection.";
}

In this modified code, the words after each case are removed The break keyword. At this time, if the value of variable $fruit is "apple", the following result will be output:

Selected fruit is apple.
Selected fruit is banana.
Selected fruit is orange.
Invalid fruit selection.

As can be seen from the above output results, when break# is not used ## keyword, PHP will execute the matching case and continue to execute subsequent cases until the Switch statement ends or the break keyword is encountered. Therefore, even if the correct case has been matched, subsequent case code blocks will be executed, which may lead to unexpected results.

Therefore, when using the Switch statement, remember to apply the

break keyword appropriately based on whether the actual situation requires terminating the execution of the current case to avoid logical errors.

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