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Table of Contents
What Does == Do?
How Is === Different?
When Should You Use Each?
Final Thoughts
Home Backend Development PHP Tutorial Explain the Difference Between `==` and `===` Operators in PHP

Explain the Difference Between `==` and `===` Operators in PHP

Jul 09, 2025 am 01:03 AM
php comparison operator

In PHP, the main difference between == and == is the strictness of type checking. The == operator performs type conversion when comparing, while === strictly checks the values ??and types without conversion. For example: "5" == 5 returns true but "5" === 5 returns false; 0 == false is true but 0 === false is false; null === 0 is always false. You should use == when the type is independent or requires flexible comparison, such as user input processing; if the type must be consistent, such as the detection function returns false, validation null or boolean flag. It is recommended to use === first to avoid logical errors caused by type conversion.

Explain the Difference Between `==` and `===` Operators in PHP

In PHP, the == and === operators are both used for comparison, but they behave differently depending on what you're comparing. The main difference lies in how strict they are about data types.

Explain the Difference Between `==` and `===` Operators in PHP

What Does == Do?

The == operator checks whether two values ??are equal after performing type juggling if necessary. This means that PHP will try to convert one or both operators to a common type before doing the comparison.

For example:

Explain the Difference Between `==` and `===` Operators in PHP
  • "5" == 5 returns true because PHP converts the string "5" into the integer 5 .
  • 0 == false returns true because false is treated as 0 in this context.
  • "abc" == 0 returns true because the string starts with non-numeric characters and is converted to 0 .

This kind of behavior can be useful, but it can also lead to unexpected results when working with mixed types.

How Is === Different?

The === operator, also known as the identity operator , checks both value and type. It doesn't perform any type conversion — both operators must be of the same type and have the same value to return true .

Explain the Difference Between `==` and `===` Operators in PHP

Examples:

  • "5" === 5 returns false because one is a string and the other is an integer.
  • 0 === false returns false because their types different.
  • null === 0 returns false , again due to different types.

Using === avoids ambiguity and helps prevent bugs caused by automatic type conversion.

When Should You Use Each?

Use == when:

  • You don't care about the exact type.
  • You're comparing user input (which often comes in string form) to numbers or booleans.
  • You want flexibility in your comparisons.

Use === when:

  • Type matters.
  • You're checking for special values ??like false , null , or -1 which might also be confused with false values.
  • Working with functions that can return false on error and also valid 0 or empty values ??(like strpos() ).

Some common cases where === is important:

  • Checking if a function returned false (eg, if (strpos($str, 'a') === false) )
  • Verifying if a variable is actually null
  • Ensuring that boolean flags haven't been misinterpreted from numeric or string values

Final Thoughts

Choosing between == and === depends on your use case. If you're not careful with == , you might run into confusing logic due to PHP's loose typing. But === gives you more control and prediction.

Generally speaking, using === is safe unless you specifically need type coercion.

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