Описание тега triple-equals
The triple-equal operator (===) refers to objects that are both equal and of the same type.
The triple-equal operator (===) refers to objects that are both equal and of the same type.
The languages JavaScript and PHP uses this syntax, with the == operator able to return true if two values are equal, even if they have different types (for example, "4 == "4"" is true), and the "===" operator returning true only if two values are equal and have equivalent types as well (such that "4 === "4"" is false but "4 === 4" is true). [1]