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The previous article introduced you to "What is a do...while loop?" And the difference with while loop? (Attached with code) 》, this article continues to introduce you to the for loop (and the difference between while loops). Don’t hesitate to come in and learn! You will definitely gain something! ! !
for loop:
The only counting type loop (higher efficiency), for for loop , it knows how many times it will loop from the beginning;
Format:
for (expression 1; expression 2; expression 3) {
Loop body (PHP statement)
}
<?php /******for 循环 唯一一个计数循环******/ for($i = 0;$i < 10; $i++){ echo $i; } ?>The code execution result is as follows:
Code analysis: According to the format written at the beginning, first define an initial variable ($i=0), then write the condition of the loop ($i
For the for loop, it is evolved from the while loop:
<?php /******for 循环 唯一一个计数循环******/ $i = 0; for(;$i < 10; ){ echo $i; $i++; } ?>The code execution result is as follows:
About the execution format of the for loop:
Execute expression 1 and initialize the variables; Execute expression 2 to determine whether the loop conditions are met; If expression 2 meets the conditions for executing the loop, then execute {} The code inside (loop body) Execute expression 3, auto-increment or decrement condition Execute expression 2, determine whether the loop condition is met
The difference between for loop and while loop:
1: Type issueWe know almost everything about the for loop, let’s take a few codes as examples:
<?php /******for 循环 唯一一个计数循环******/ $i = 0; for(;$i < 10; ){ echo $i; $i++; } echo '<hr>'; echo '<table border="1" align="center" width="800">'; for($tr = 0;$tr<10;$tr++){ echo '<tr>'; for($td = 0;$td<10;$td++){ echo '<td>'.$tr.$td.'</td>'; } echo '</tr>'; } echo '</table>'; ?>Code running The results are as follows: Recommended learning: "
PHP Video Tutorial"
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