Analysis of new features of PHP8: How to use str_contains function and code to simplify string judgment?

Analysis of new features of PHP8: How to use str_contains function and code to simplify string judgment?

PHP is a widely used open source scripting language for web development. Each PHP version release brings new features and improvements. PHP8 is the latest version released, which brings many new features while also providing more convenience for developers. One of the exciting new features is the str_contains function, which provides us with an easy way to determine whether a string contains a specified substring. This article will analyze the usage of str_contains and show how to use it and other code to simplify string judgment.

In the past, we usually used the strpos function to determine whether a string contains another string. It will return the starting position of the containing substring, and compare it with false to determine whether it is included. However, this approach can become lengthy and complex in some cases. For example, if we want to determine whether a string contains multiple substrings, we need to repeatedly write multiple strpos function calls and perform multiple comparisons. Not only does this increase code size and maintenance costs, but it can also lead to errors.

In PHP8, the str_contains function was introduced to solve this problem. It can more directly determine whether a string contains another string, returning a Boolean value. Here is a simple example:

$string = "Hello, world!";
$substring = "world";

if (str_contains($string, $substring)) {
    echo "包含子字符串";
} else {
    echo "不包含子字符串";
}

In the above example, we use str_contains function to check if $string contains $substring. If it is included, output "Contains substring", otherwise output "Does not contain substring". Is it more concise and clear than using the strpos function? In addition, the str_contains function can also be very conveniently used to judge multiple substrings:

$string = "Hello, world!";
$substrings = ["world", "hello", "foo"];

foreach ($substrings as $substring) {
    if (str_contains($string, $substring)) {
        echo "包含子字符串: " . $substring . "
";
    } else {
        echo "不包含子字符串: " . $substring . "
";
    }
}

In the above example, we traverse the $substrings array and use the str_contains function to check whether $string contains each substring. Based on the results, we output the corresponding information. This approach is more concise and easier to understand than reusing the strpos function and multiple comparisons.

However, it should be noted that the str_contains function is new to PHP8. If your project is still using an older PHP version, it will cause compatibility issues. Therefore, before using the str_contains function, please make sure that your PHP version meets the requirements.

In addition to the str_contains function, PHP8 also introduces some other new features related to string operations. For example, the str_starts_with and str_ends_with functions can respectively determine whether a string begins with a specified prefix or suffix. Their usage is similar to the str_contains function, which can further simplify the judgment logic.

In summary, the new features of PHP8 provide us with a more concise and intuitive way to determine whether a string contains a specified substring. By using the str_contains function and other new features, we can reduce the amount of code and improve code quality and readability. However, we also need to pay attention to the compatibility of PHP versions to ensure that our code can run normally in different environments. If you are using PHP8 or are about to upgrade to this version, you may wish to try the str_contains function and other new features to experience the convenience they bring!

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