What does == mean in php

The == operator in PHP compares whether the values ​​of two expressions are equal. It compares values ​​and types according to rules, performs type conversions to match unequal types, and returns true (equal) or false (not equal). Unlike the === operator, the latter does not convert types and returns true only if the value and type are equal.

The meaning of == in PHP

== in PHP is an equality comparison operator, used for comparison Whether the values ​​of two expressions are equal.

Usage

== operator compares two expressions according to the following rules:

• If the values ​​of the expressions are of the same type (e.g., integers, strings, floating point numbers), their values ​​are compared directly.
• If the expressions are of different types, PHP will convert one of the types to match the other.
• The comparison result will be true (equal) or false (not equal).

The difference between ===

There is another equality comparison operator === in PHP, which is similar to ==, but more advanced strict. === does not perform a type conversion and returns true only if the expressions are equal in value and type.

Examples

Here are some examples of using the == operator:

var_dump(1 == 1); // 输出：true
var_dump("foo" == "foo"); // 输出：true
var_dump(1.0 == 1); // 输出：true
var_dump(true == 1); // 输出：true

It should be noted that the following comparisons will return false because they have different values ​​or types:

var_dump(1 == "1"); // 输出：false
var_dump(1.0 == 1.1); // 输出：false
var_dump(true == false); // 输出：false

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