1.6 KiB
1.6 KiB
title | localeTitle |
---|---|
Learn About Php Loops | 了解Php循环 |
循环是执行指定次数的代码块。使用循环减少了代码行数。
PHP适用于4种不同类型的循环:
- 循环
- 做... while循环
- 对于循环
- Foreach循环
循环
只要指定的条件为真, while
循环就会继续执行。
`PHP
Example:
```php
<?php
$x = 1;
while($x <= 3)
{
echo "x=$x ";
$x++;
}
?>
Output:
x=1 x=2 x=3
Do...while loop
In the do...while
loop the block of code is executed before the condition is checked.
<?php
do {
execute code;
} while (condition);
?>
Example:
<?php
$x= 1;
do {
echo "x=$x ";
$x++;
} while ($x < 5);
?>
Output:
x=1 x=2 x=3 x=4
For loop
The for
loop is used when the number of times the block is to be executed is known in advance.
<?php
for (variable initialisation; test condition; increment)
{
execute code;
}
?>
Example:
<?php
for ($x=1 ; $x <= 4 ; $x++)
{
echo "x= $x ";
}
?>
Output:
x=1 x=2 x=3 x=4
Foreach loop
The foreach
loop helps in traversing through arrays.
<?php
foreach ($array as $value)
{
executable code;
}
?>
Example:
<?php
$numbers= array("One", "Two", "Three");
foreach ($numbers as $value)
{
echo "$value ";
}
?>
Output:
One Two Three