Analyzing the while() loop in php (with code examples)

Branch statements in PHP are relatively basic grammatical knowledge. while() Loops are also a solution to reduce repeated operations. This article will introduce Let’s take a look together. First, let’s take a look at the syntax of the while() loop:

while (expr)                或者       while (expr):
  statement                                    statement
                                             ...
                                            endwhile;

As long as while the value of the expression is true Repeat the nested loop statement. The value of the expression is checked each time the loop starts, so even if the value changes during the loop statement, execution of the statement will not stop until the end of the loop. If the value of the while expression is false at the beginning, the loop statement will not be executed even once.

Code example:

1. Use curly braces

<?php
    $a=0;
    $sum=0;
    while($a<=50){
          $sum+=$a;
          $a++;
      }
    echo $sum;
?>

输出：1275

2. Use alternative syntax

<?php
$a=0;
$sum=0;
while($a<=50):
  $sum+=$a;
  $a++;
endwhile;
echo $sum;
?>

输出：1275

Recommended: 《2021 PHP Interview Questions Summary (Collection) 》《php video tutorial》

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