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This article mainly explains "what is the difference between false and 0 in php". The content of the explanation in the article is simple and clear, and it is easy to learn and understand. Please follow the editor's train of thought to study and learn "what is the difference between false and 0 in php".

The difference between php false and 0: 1. False is a Boolean value, while 0 is the value 0. In PHP, false is stored with a value of 0, but the type of false and 0 is not the same.

The operating environment of this paper: Windows7 system, PHP7.1, Dell G3.

What is the difference between php false and 0?

The difference between 0 and empty Null false in php

The reason is that variables are stored in C language structure in PHP, empty string and NULL,false are stored with a value of 0, where this structure has a member variable such as zend_uchar type;, which is used to hold the type of variable, while the type of empty string is string,NULL and the type of NULL,false is boolean.

You can use echo gettype (''); and echo gettype (NULL); to print this! The = operator not only compares values, but also compares types, so the third one is false!

So it can be said that = = is equal to the following function:

Function eq ($v1, $v2) {if ($v1 = = $v2 & & gettype ($v1) = = gettype ($v2)) {return 1;} else {return 0;}}

So the empty string (''), false,NULL and 0 are equal values but different types!

Note:

NULL is a special type.

NULL in both cases

1. $var = NULL

2. $var

3. "," 0, "0", NULL, FALSE, array (), var $var;, and objects without any attributes will be considered empty, and TRUE will be returned if var is empty.

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