Functions in PHP8: Practical tips for str_contains()

The new str_contains() function in PHP8 is a very practical string processing function. It can quickly determine whether a string contains a certain substring. In practical applications, it can help us quickly locate keywords in the data, allowing for more efficient data processing and analysis. This article will introduce the basic usage of the str_contains() function, and combine it with actual cases to show how to use this function for string processing and analysis.

1. Overview of str_contains() function

The str_contains() function is a new string function in PHP8. Its function is to determine whether a string contains a specified substring. It is defined as follows:

bool str_contains(string $haystack, string $needle)

Among them, $haystack represents the main string to be judged, and $needle represents the substring to be found. The function return value is of Boolean type, returning true when the main string contains a substring, otherwise it returns false.

In practical applications, the str_contains() function is very practical and can be used to determine whether the specified string contains specific keywords, check whether the file name contains the specified suffix name, etc.

2. Basic usage of str_contains() function

str_contains() function is very simple and easy to use. Let’s take a look at an example of its basic usage:

$str1 = "Hello, world!";
$str2 = "lo";
if(str_contains($str1, $str2)){
    echo "The string contains 'lo'.";
}else{
    echo "The string does not contain 'lo'.";
}

Above In the example, we define two string variables $str1 and $str2, and then use the str_contains() function to determine whether $str1 contains the substring defined in $str2. If it is contained, then the string "The string contains 'lo'." is output, otherwise the string "The string does not contain 'lo'." is output.

3. Actual case: Check whether the file name contains the specified suffix name

Next, we will combine actual cases to demonstrate how to use the str_contains() function for string processing and analysis. Assume that our application needs to read all the files in a certain directory, and then check whether the file name contains the specified suffix name. If it does, perform the corresponding processing, otherwise the file will be skipped. The following is an implementation code example:

<?php
$dir = "/path/to/files/";         //定义要读取的文件目录
$ext = ".txt";                     //定义要检查的后缀名
if (is_dir($dir)) {                  //判断目录是否存在
    if ($dh = opendir($dir)) {        //打开目录
        while (($file = readdir($dh)) !== false) {   //循环读取目录下所有文件
            if(str_contains($file, $ext)){      //判断文件名中是否包含指定后缀名
                //进行相应的处理
                echo "Processing file: ".$file."
";
            }else{
                continue;                  //如果不包含则跳过该文件的处理
            }
        }
        closedir($dh);                   //关闭目录句柄
    }
}
?>

In the above example, we define the file directory $dir to be read and the suffix name $ext to be checked. Then we use the is_dir() function to determine whether the directory exists, use the opendir() function to open the directory, and use the readdir() function to read all files in the directory. In the loop, we use the str_contains() function to determine whether the file name contains the specified suffix name. If it does, the file name will be output and processed accordingly, otherwise the file will be skipped.

Through the above example, we can see that the str_contains() function is very practical and can help us quickly locate keywords in the data and play an important role in string processing and analysis.

4. Summary

The str_contains() function newly added in PHP8 is a very practical string processing function that can quickly determine whether a string contains a certain substring. In practical applications, it can help us quickly locate keywords in the data, allowing for more efficient data processing and analysis. Through the introduction and examples of this article, I believe you have mastered the basic usage and practical application skills of the str_contains() function. I hope it will be helpful to you.

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