Difference between php array_key_exists () and isset (), issetarraykeyexists

Difference between php array_key_exists () and isset (), issetarraykeyexists

Php array_key_exists is used to check whether a key name exists in the array, and isset can also be used to check whether a key name exists in the array. What is the difference between them? This article will explain the differences between array_key_exists () and isset ().

The basic difference is that isset () can be used for arrays and variables, while array_key_exits () can only be used for arrays.

However, the main difference is the return value under the specified conditions.

Now let's verify the main difference.

Array_key_exists ()

Array_key_exists () checks the existence of the key value. This function returns TRUE if the key value exists, even if the value is NULL.

$arr = array( "one"=>"1", "two"=>"2", "three"=>null ); array_key_exists("one", $arr); // true array_key_exists("two", $arr); // true array_key_exists("three", $arr); // true

Isset ()

Unlike arrry_key_exitst (), isset () checks the key and value at the same time. It returns true only when the key exists and the corresponding variable is not NUll.

$arr = array( "one"=>"1", "two"=>"2", "three"=>null );isset($arr["one"]); // true isset($arr["two"]); // true isset($arr["three"]); // false 

Conclusion

This article describes the main differences between the two functions mentioned above. pay more attention when using these two functions in the future!

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