How to detect whether there are keywords in a php array

In PHP, arrays are a very important data type. They can be used to store multiple values, usually in the form of key-value pairs. In actual development, we often need to detect arrays to determine whether they contain specified keywords. This article will introduce how to use PHP arrays to detect whether keywords are included.

1. Use the in_array() function

The in_array() function in PHP can be used to detect whether a value is in an array. It accepts two parameters: the value to be found value and the array to search for. The function returns TRUE if the value being found exists in the array, otherwise it returns FALSE. The following is a simple example:

$keywords = array('php', 'mysql', 'html', 'css');
if(in_array('php', $keywords)){
    echo "数组中包含 'php' 关键字。";
} else {
    echo "数组中不包含 'php' 关键字。";
}

The output result is "The array contains the 'php' keyword.". In this code, we define an array $keywords containing four keywords, and use the in_array() function to check whether it contains the 'php' keyword. Since the array does contain 'php', the output is TRUE.

2. Use array_search() function

array_search() function is similar to in_array() function, but the difference is that it returns the matching key name instead of returning TRUE or FALSE. If the keyword is not found, returns FALSE. The following is an example:

$keywords = array('php', 'mysql', 'html', 'css');
$position = array_search('mysql', $keywords);
if($position !== FALSE){
    echo "'mysql' 关键字在数组中的位置为： $position。";
} else {
    echo "数组中不包含 'mysql' 关键字。";
}

The output result is "The position of the 'mysql' keyword in the array is: 1.". In this example, we search for the 'mysql' keyword and use the array_search() function to find the position of that keyword in the array. Since 'mysql' exists in the second position of the array, the output is 1.

3. Use isset() function

isset() function is used to check whether a variable has been set and non-NULL. If the variable exists and the value is not NULL, then The isset() function returns TRUE, otherwise it returns FALSE. You can use the isset() function to determine whether a specified keyword exists in an array. The following is an example:

$keywords = array('php', 'mysql', 'html', 'css');
if(isset($keywords['php'])){
    echo "数组中包含 'php' 关键字。";
} else {
    echo "数组中不包含 'php' 关键字。";
}

The output result is "The array contains the 'php' keyword.". In this example, we use the isset() function to determine whether the 'php' keyword is present in the array. Since the array does contain 'php', the output is TRUE.

Summary

In PHP, you can use the in_array() function, array_search() function, and isset() function to determine whether an array contains a specified keyword. Either way, you can perform this operation quickly and accurately. In actual development, please choose which method to use based on your actual situation and personal preferences.

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