What does three equals mean in php

The three equal signs (===) in PHP are called strict equality operators, which are used to compare whether the values ​​and types of two expressions are exactly the same. It helps prevent accidental type conversions and ensures accurate comparisons. The strict equality operator differs from the ordinary equals operator (==) in that the latter does type conversion when comparing values, while the strict equality operator does not.

The meaning of the three equal signs (===) in PHP

The three equal signs in PHP (===) is called the strict equality operator and is used to compare whether the values ​​of two expressions are exactly the same, including value and type.

The role of the strict equality operator:

• Compare values ​​and types: The strict equality operator not only compares the values ​​of expressions, Also compare their types.
• Distinguish between different types of values: For example, it can distinguish between the number 0 and the string "0", even if their values ​​are the same.
• Prevent unexpected type conversions: It helps prevent unexpected type conversions when comparing values ​​of different types.

Example:

<code class="php">var_dump(0 === "0"); // false
var_dump(0.0 === "0"); // false
var_dump("1" === 1); // false</code>

The difference from the ordinary equal sign (==):

Ordinary equal sign (==) is a loose equality operator that performs type conversion when comparing values, allowing values ​​of different types to be equal.

<code class="php">var_dump(0 == "0"); // true
var_dump(0.0 == "0"); // true
var_dump("1" == 1); // true</code>

When to use the strict equality operator:

The strict equality operator should be used when the values ​​and types of two expressions need to be strictly compared. This is particularly important in the following situations:

• Ensuring the accuracy of comparisons
• Preventing accidental type conversions
• Comparing complex data structures such as objects or arrays

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