How to verify that the value of an array is a space in php

In PHP, we often need to verify whether the value in the array is a space. When the value in the array is a space, using the regular null value check will fail. This article will introduce how to use PHP to verify whether the value in an array is a space.

1. Use the trim() function

The trim() function can check whether the head and tail of the string contain spaces, and remove them if they do.

We can use this function to check whether the value in the array is a space, as shown below:

$array = array(' ', 'hello', 'world', '');

foreach ($array as $value) {
    if (trim($value) == '') {
        echo '数组值为空格' . "
";
    } else {
        echo '数组值为' . $value . "
";
    }
}

In the above code, we have used the trim() function to check each value in the array Whether the value is a space. If so, output "array value is space". Otherwise, the array value itself is output.

2. Using regular expressions

We can use regular expressions to check whether the value in the array is a space. Spaces can be represented by "s" in regular expressions, as shown below:

$array = array(' ', 'hello', 'world', '');

foreach ($array as $value) {
    if (preg_match('/^s*$/', $value)) {
        echo '数组值为空格' . "
";
    } else {
        echo '数组值为' . $value . "
";
    }
}

In the above code, we use the preg_match() function and the regular expression "/^s*$/" to check the array Whether each value in is a space. If so, output "array value is space". Otherwise, the array value itself is output.

3. Use the ctype_space() function

The ctype_space() function can check whether a character is a space character (including space, tab, newline, etc.). We can use this function to check whether the value in the array is a space character or not as shown below:

$array = array(' ', 'hello', 'world', '');

foreach ($array as $value) {
    if (ctype_space($value)) {
        echo '数组值为空格' . "
";
    } else {
        echo '数组值为' . $value . "
";
    }
}

In the above code, we use the ctype_space() function to check whether each value in the array is a space character or not. If so, output "array value is space". Otherwise, the array value itself is output.

Summary

This article introduces three methods to verify whether the value in a PHP array is a space: using the trim() function, using regular expressions, and using the ctype_space() function. These methods can help us easily check whether the value in the array is a space, ensuring the correctness and stability of the program.

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