== Is used for the comparison between two variables regardless of the type of the variable.
=== Is used for a strict comparison between two variables i.e. it will check the type and value of both variables, which means it will check the type and compare the two values.
Example of the assignment operator =
var nombre = 25;
Exemple de l’opérateur de comparaison ==
The ‘==’ operator tests for abstract equality, it performs the necessary type conversions before making the equality comparison.
// string "15" is converted to integer 15 if (nombre == "15") alert("Both are equal"); else alert("The two are not equal");
Both are equal
Example of the comparison operator ===
The ‘===’ operator tests for strict equality, it will not do the type conversion, so if the two values are not of the same type, it will return “false”.
// Aucune conversion de type n'a lieu if (nombre === "15") alert("Both are equal"); else alert("The two are not equal");
The two are not equal
Usually the ‘===’ operator is recommended because it never does a type conversion, we do an exact comparison, so it always produces correct results.