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Two methods for PHP to fill an array: 1. Fill the array to the specified length with the specified value through array_pad(), the syntax is "array_pad(original array, length, specified value)". 2. Fill the array to the specified length with the specified value through array_fill(), the syntax is "array_fill (start filling position, filling length, specified value)".
The operating environment of this tutorial: windows7 system, PHP version 8.1, DELL G3 computer
PHP provides 2 types of fill arrays Function to a specified length:
array_pad(): Fills an array with a given value
array_fill(): To fill Create a new array using the data method
1. Use array_pad() to fill the array
array_pad() function can fill the array with a certain value to the specified length, the syntax is as follows:
array array_pad ( array $arr, int $size , mixed $value )
Parameter description:
array_pad() function will fill the array arr to the length size with the value value.
Return value: Return the filled array. The returned array is just a copy, the original array will not be changed.
Usage examples are as follows:
<?php header('content-type:text/html;charset=utf-8'); $arr = array(12, 10, 9); $result = array_pad($arr, 5, 0); //从数组右侧开始, 用0填补数组到含有5个元素 var_dump($result); $result = array_pad($arr, -7, -1); //从数组左侧开始, 用-1填补数组到含有7个元素 var_dump($result); $result = array_pad($arr, 2, "noop"); // 第二个参数小于数组长度, 不填补 var_dump($result); ?>
2. Use array_fill() to fill the array
array_fill() function A new array will be created by filling data, or a certain value will be used to fill the array to the specified length. The syntax is as follows:
array array_fill ( int $start_index , int $num , mixed $value )
Parameter description:
array_fill() will create a new array containing num elements, where the value of each element is value. Unlike array_pad(), array_fill() creates a new array by filling it, rather than based on the original array.
Return value: Return the new array after filling.
Usage examples are as follows:
<?php header('content-type:text/html;charset=utf-8'); $a = array_fill(5, 6, 'banana'); //使用banana填充数组到6个元素, 索引键由数字5开始 $b = array_fill(-2, 4, 'pear'); //使用pear填充数组到4个元素, 索引键由-2开始 $c = array_fill(3, 2, array(1,2,3)); // 用一个数组填充成一个二维数组 var_dump($a); var_dump($b); var_dump($c); ?>
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