What does else mean in php

In PHP, else means "other". The else statement is a clause of the if statement. The corresponding statement can be executed when the value of the expression in the if statement is FALSE; the else statement must be together with the if statement. used and cannot exist alone. Syntax "if (judgment condition) {statement block 1;} else {statement block 2;}".

The operating environment of this tutorial: windows7 system, PHP7.1 version, DELL G3 computer

if Statements can only perform operations when the judgment result is true, which is not enough in many cases, so there are statements in the form of if...else. Different from the if judgment, the if...else statement not only performs operations on the situation where the judgment result is true, but can also perform corresponding operations on the situation where the judgment result is not true.

The else statement extends the if statement and can execute the corresponding statement when the value of the expression in the if statement is FALSE. Another thing to note is that the else statement is a clause of the if statement and must be used together with the if statement and cannot exist alone.

The syntax format of the if...else statement is as follows:

if (判断条件) {
    语句块 1;
} else {
    语句块 2;
}

In the above format, if the "judgment condition" is true, then execute "statement block 1"; otherwise, execute "statement Block 2". Both "Block 1" and "Block 2" can contain multiple statements. The same as the if statement, if both "Statement Block 1" and "Statement Block 2" contain only one statement, the curly brackets { } can be omitted, as follows:

if (判断条件)
    语句块 1;
else
    语句块 2;

if...else The execution flow of the statement is shown in the figure below:

Example: Use the rand() function to generate a random number $num, and then determine whether the random number is Even number or odd number, the code is as follows:

<?php
    $num = rand(1,31);  //生成一个 1~31 之间的随机数
    if ($num % 2 == 0) {
        echo &#39;$num =&#39;.$num.&#39;, 是偶数！&#39;;
    } else {
        echo &#39;$num =&#39;.$num.&#39;, 是奇数！&#39;;
    }
?>

The running results are as follows:

$num =27, 是奇数！

Recommended learning: "PHP Video Tutorial"

The above is the detailed content of What does else mean in php. For more information, please follow other related articles on the PHP Chinese website!