What is JavaScript Triple Equals?
The triple-equal operator in JavaScript is used to check for strict equality between two values. Unlike the double-equal operator, the triple-equal operator does not perform type conversion when comparing values of different types. When using "===", if the values being compared are not of the same type, the operation will result in false. This indicates that the triple-equal operator checks for equality without considering type coercion, requiring both the type and the values to be identical for the comparison to return true.
Put simply, the triple equals operator does not apply any coercion. It checks if the variables being compared have both identical values and matching types.
When working with JavaScript, the triple equals operator has two key principles to consider: strict equality applies to the comparison of primitive values, while reference equality is used when comparing reference values.
Strict Equality
In JavaScript, strict equality allows us to verify if both the type and value are identical. When the type matches but the values differ, the result is false. Similarly, if the values match but the types do not, the result will also be false. Only when both the type and value are identical, the result will be true.
Example:
5 === 5; // true. Same type, same value.
5 === 4; // false. Same type, different values.
5 === "5"; // false. Different type, same value.
true === true; // true. Same type, same value.
true === false; // false. Same type, different values.
true === "true"; // false. Different type, same value.
Reference Equality
In the example shown earlier, primitives are compared based on their values. In JavaScript, when we employ triple equals for reference equality, it compares the references or locates them in memory.
Example:
{} === {} // false. Same type, similar value, and different references.
[] === [] // false. Same type, similar value, and different references.
{ name: 'Rohit' } === { name: 'Rohit' } // false. Same type, similar value, and different references.
Difference between the Double equals and Triple Equals
Distinguishing between double equals (==) and triple equals (===) in JavaScript:
Comparison in JavaScript:
- Double Equals: The double equals operator in JavaScript compares the values of two variables without considering their datatypes.
- Triple Equals: On the other hand, the triple equals operator in JavaScript not only compares the values of two variables but also checks their datatypes.
Coercion
- Using the double equals operator involves coercion.
- On the other hand, the triple equals operator does not involve coercion.
Type Casting
- Loose Equality: Within JavaScript, it automatically changes the type for executing an operation.
- Strict Equality: Unlike loose equality, strict equality does not alter the original data types during comparisons.
Dynamically or Strongly typed
- Using the double equals sign indicates dynamic typing.
- Employing the triple equals sign signifies strong typing.
The benefits of using JavaScript triple equals
When working with JavaScript, the triple equals operator plays a crucial role in conducting strict equality comparisons. This operator allows for the comparison of both the value and the type of two variables, ensuring that they are exactly the same in both aspects. Below are a few advantages of utilizing the triple equals operator:
Type Safety
In JavaScript, the triple equals operator differs from the double equals operator by enforcing strict type checking. When using triple equals, both variables in comparison must be of the same type to return true. This approach aids in avoiding unintended outcomes caused by implicit type conversion.
0 == '0'; // true, because '0' is coerced to number 0
0 === '0'; // false, because the types are different
Predictability
When working with JavaScript, the strict equality operator (===) is preferred over the loose equality operator (==) because it does not coerce the types of values being compared. This leads to code that is more predictable and easier to comprehend. By using ===, it ensures that a comparison will only return true if both operands are of the same type and have the same value.
Avoiding Bugs
By utilizing strict equality, we can prevent subtle errors that may occur due to unintentional type conversions. This approach is especially valuable in situations where maintaining type consistency is crucial.
'5' == 5; // true, because '5' is coerced to number 5
'5' === 5; // false, because the types are different
Consistency
Consistently utilizing the triple equals (===) operator in JavaScript is crucial for establishing a cohesive and standardized coding convention. This practice guarantees that all comparisons are unequivocal and deliberate, consequently minimizing the likelihood of errors.
Performance
In JavaScript, although the difference in performance is typically minimal for the majority of applications, === may exhibit slightly better speed compared to == since it eliminates the need for an additional type conversion step.
Employing the strict equality operator (===) in JavaScript contributes to the development of more resilient, reliable, and sustainable code by steering clear of the issues associated with type coercion.