Whether a php two-dimensional array contains a field

In PHP programming, arrays are a very common data type, and two-dimensional arrays are even more common. What should we do when we need to search for a specific field in a two-dimensional array? This article will share how to determine whether a PHP two-dimensional array contains a certain field.

1. What is a php two-dimensional array?

In php, arrays can save multiple values. If the values ​​in an array are themselves an array, then the array is called a two-dimensional array. For example:

$fruits = array(
    array("apple", "red"),
    array("banana", "yellow"),
    array("grape", "purple"),
);

In the above code, $fruits is a two-dimensional array containing three arrays, each array containing two values.

2. Methods to determine whether a two-dimensional array contains a certain field

There are many ways to determine whether a PHP two-dimensional array contains a certain field. Here are two common methods: Method:

1. Use the in_array() function

function check_array($arr, $key, $value){
    foreach($arr as $item){
        if(in_array($value, $item) && in_array($key, $item)){
            return true;
        }
    }
    return false;
}

Use the in_array() function to traverse the two-dimensional array. If the two-dimensional array contains $key and $value, return true, otherwise return false. It should be noted that this method can only determine the position of the value in the array, not the key name.

Usage method:

$people = array(
    array("name" => "Tom", "age" => 18),
    array("name" => "Lily", "age" => 20),
    array("name" => "Lucy", "age" => 22),
);

if(check_array($people, "name", "Tom")){
    echo "包含Tom的人员信息";
}else{
    echo "不包含Tom的人员信息";
}

2. Use foreach() loop

function check_array($arr, $key, $value){
    foreach ($arr as $k => $v) {
        if ($v["$key"] == $value) {
            return true;
        }
    }
    return false;
}

Use foreach() loop to traverse the two-dimensional array and determine whether there is a $ in the two-dimensional array. key is the key name and the value is the array element of $value. If it exists, return true, otherwise return false.

Usage:

$people = array(
    array("name" => "Tom", "age" => 18),
    array("name" => "Lily", "age" => 20),
    array("name" => "Lucy", "age" => 22),
);

if(check_array($people, "name", "Tom")){
    echo "包含Tom的人员信息";
}else{
    echo "不包含Tom的人员信息";
}

3. Summary

In PHP programming, two-dimensional array is a common data type. When you need to determine whether a two-dimensional array contains a certain field, you can use the in_array() function or foreach() loop to determine. The appropriate method needs to be chosen based on specific business needs.

The above is the detailed content of Whether a php two-dimensional array contains a field. For more information, please follow other related articles on the PHP Chinese website!