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PHP Loops - Understanding and Using While Loops

jacklove

May 07, 2018 am 11:35 AM

phpwhileuse

PHP Loop - While loop plays an important role in php, this article will give some explanations about it.

PHP Loops

When you write code, you often need to have the same block of code run over and over again. We can use loop statements in our code to accomplish this task.

In PHP, the following loop statements are provided:

while - As long as the specified condition is true, the code block will be executed in a loop

do...while - Executed once block of code, and then repeats the loop when the specified condition is true

for - Loops to execute the code block a specified number of times

foreach - Based on array Loop through each element in the code block

while loop

The while loop will repeatedly execute the code block until the specified condition is not true.

Syntax

while (condition){
Code to be executed;}

Example

The following example first sets the variable i The value is 1 ($i=1;).

Then, as long as i is less than or equal to 5, the while loop will continue to run. Each time the loop runs, i will be incremented by 1:

<html><body><?php
$i=1;while($i<=5){
    echo "The number is " . $i . "<br>";
    $i++;}?></body></html>

Output:

The number is 1
The number is 2
The number is 3
The number is 4
The number is 5

do...while statement

do...while statement will execute the code at least once, then check the condition, and repeat as long as the condition is true cycle.

Syntax

do{
    要执行的代码;}while (条件);

Example

The following example first sets the value of variable i to 1 ($i=1;).

Then, start the do...while loop. The loop increments the value of variable i by 1 and then outputs it. First check the condition (i is less than or equal to 5), as long as i is less than or equal to 5, the loop will continue to run:

<html><body><?php
$i=1;do{
    $i++;
    echo "The number is " . $i . "<br>";}while ($i<=5);?></body></html>

Output:

The number is 2
The number is 3
The number is 4
The number is 5
The number is 6

This article provides some detailed explanations of php loops and while loops for more learning Please follow the php Chinese website to view the information.

Related recommendations:

Detailed explanation of php magic variable usage examples, detailed explanation of php magic examples_PHP tutorial

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