List of PHP flow control statements

The flow control statement in PHP is an indispensable part when writing a program. It can control the execution flow of the program and execute different code blocks according to different conditions. This article will introduce commonly used flow control statements in PHP, including if statements, switch statements, for loops, while loops and foreach loops, and provide specific code examples.

if statement

The if statement is the most basic flow control statement in PHP, which can execute different code blocks based on given conditions. The basic format of the if statement is as follows:

if (condition) {
    // 如果条件为真，则执行这里的代码
} elseif (condition2) {
    // 如果条件2为真，则执行这里的代码
} else {
    // 如果以上条件都不满足，则执行这里的代码
}

The following is an example of an if statement:

$score = 90;

if ($score >= 60) {
    echo "及格";
} else {
    echo "不及格";
}

switch statement

The switch statement is used to select and execute different actions based on the value of the expression. code block. The basic format of the switch statement is as follows:

switch (value) {
    case label1:
        // 如果value等于label1，则执行这里的代码
        break;
    case label2:
        // 如果value等于label2，则执行这里的代码
        break;
    default:
        // 如果以上条件都不满足，则执行这里的代码
}

The following is an example of a switch statement:

$day = "Monday";

switch ($day) {
    case "Monday":
        echo "星期一";
        break;
    case "Tuesday":
        echo "星期二";
        break;
    default:
        echo "其他";
}

for loop

The for loop is used to execute a specific number of loops. The basic format of a for loop is as follows:

for (initialization; condition; increment) {
    // 循环体
}

The following is an example of a for loop:

for ($i = 0; $i < 5; $i++) {
    echo $i;
}

while loop

The while loop executes the loop when the condition is true. The basic format of the while loop is as follows:

while (condition) {
    // 循环体
}

The following is an example of a while loop:

$i = 0;
while ($i < 5) {
    echo $i;
    $i++;
}

foreach loop

The foreach loop is used to iterate through each element in the array. The basic format of the foreach loop is as follows:

foreach ($array as $value) {
    // 循环体
}

The following is an example of a foreach loop:

$colors = array("red", "green", "blue");

foreach ($colors as $color) {
    echo $color;
}

To sum up, the flow control statements in PHP include if statements, switch statements, for loops, While loops and foreach loops can select appropriate statements according to different needs to implement program logic control. Through the code examples provided in this article, readers can better understand and apply these flow control statements.

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