PHP 7 performance optimization tips: How to use the is_null function to determine whether a variable is null

PHP 7 Performance Optimization Tips: How to use the is_null function to determine whether a variable is null

In PHP development, we often need to determine whether a variable is null. In past PHP versions, we usually used the "===" operator to determine whether a variable is null. However, with the release of PHP 7, we introduced a new function is_null() to make this judgment more efficiently.

The is_null() function is a built-in function that can detect whether a variable is null. It returns a boolean value that returns true if the variable is null or false if the variable is not null.

The following is a code example that uses the is_null() function to determine whether a variable is null:

$var1 = null;
$var2 = "Hello World";

if(is_null($var1)) {
    echo "var1 is null";
} else {
    echo "var1 is not null";
}

if(is_null($var2)) {
    echo "var2 is null";
} else {
    echo "var2 is not null";
}

In the above example, we defined two variables $var1 and $var2. The value of $var1 is null, and the value of $var2 is "Hello World". By calling the is_null() function, we can easily determine whether these two variables are null and perform corresponding processing based on the judgment results.

One of the benefits of using the is_null() function to determine whether a variable is null is that its execution efficiency is higher than using the "===" operator. In fact, there are two reasons why the is_null() function is more efficient than the "===" operator:

First, the is_null() function only needs to judge the variable once, while the "===" operator The character needs to be judged twice. When using the "===" operator to determine whether a variable is null, you need to determine the value type and value of the variable in turn. The is_null() function directly detects whether the variable is null without making additional judgments.

Secondly, the is_null() function calls a built-in function, and the "===" operator is an operator. When PHP parses and executes code, calling functions is usually less expensive than executing operators. Therefore, using the is_null() function to determine whether a variable is null can improve the execution efficiency of the code.

To summarize, using the is_null() function can more efficiently determine whether a variable is null. Although the same effect can be achieved using the "===" operator in some cases, using the is_null() function can improve the readability and execution efficiency of the code. In PHP 7, especially for scenarios that require frequent judgment of whether a variable is null, we recommend using the is_null() function.

I hope this article will help you understand and master the is_null() function in PHP 7 performance optimization skills. Good luck writing more efficient PHP code!

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