How to query elements of an array that meet conditions in php

Detection steps: 1. Customize a callback function to set the conditions for processing array elements, filter the array, and return elements that meet the conditions. The syntax is "function f($num){return(specified condition);} "; 2. Use array_filter() to call the callback function to process the specified array and obtain elements that meet the conditions. The syntax is "array_filter($arr, "f")".

The operating environment of this tutorial: windows7 system, PHP8 version, DELL G3 computer

In PHP, you can use the array_filter() function to query the array Eligible elements.

php array_filter() function introduction

array_filter() function uses the callback function to filter the elements in the array and returns a filtered array.

This function passes each key value in the input array to the callback function. If the callback function returns true, the current key value in the input array is returned to the result array. Array key names remain unchanged.

array array_filter ( $array , 回调函数 )

php array_filter() function queries the array elements that meet the conditions

• Step 1: Customize a callback function to set and process array elements Conditions, return elements that meet the conditions

function f($num){
     return(指定条件);
}

• Step 2: Use the array_filter() function to call the callback function to filter the array and obtain elements that meet the conditions

  array_filter() filters the array and returns elements with symbolic conditions

array_filter($arr,"f");

will return a filtered array containing all elements that meet the conditions

Example:

0); //条件是 大于0的元素
}
$arr=array(2,-1,0,-8,-10,-5,9);
echo "原数组：";
var_dump($arr);

echo "符合条件的元素有：";
$res=array_filter($arr,"f");
var_dump($res);

?>

Recommended learning: "PHP Video Tutorial"

The above is the detailed content of How to query elements of an array that meet conditions in php. For more information, please follow other related articles on the PHP Chinese website!