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Understanding Equality Operators in JavaScript

In this video, I explain the different types of equality operators in JavaScript and how to avoid unexpected bugs by using the right one.

Key Concepts Covered

1. Declaring a Variable

const myVar = 10;

2. Using `console.log()` to Check Equality

Basic comparison using triple equals (===):

console.log(myVar === 10); // true

Checks both value and type.

3. Inequality Operator

console.log(myVar !== 10); // false

The !== operator means "not equal in value or type."

4. Double Equals (`==`) vs. Triple Equals (`===`)

console.log(myVar == "10");  // true (because of type coercion)
console.log(myVar === "10"); // false (type mismatch)

== performs type coercion (tries to convert the types to match).
=== does strict comparison (value and type must match).

5. Weird Behavior with Boolean Comparisons

console.log(true == 1);  // true
console.log(false == 0); // true

console.log(true === 1);  // false
console.log(false === 0); // false

== coerces true to 1 and false to 0.
=== keeps types intact and results in false.

6. Best Practices

Always use === and !== to avoid unexpected results from type coercion.
Avoid using == or != unless you explicitly want loose comparison (rare in practice).

Summary

== compares values only, and will try to convert types if they don’t match.
=== compares both value and type, making it safer and more predictable.
To avoid bugs and confusion, always use === and !== unless you have a very specific reason not to.

Example to test your understanding:

const value = "1";
console.log(value == 1);  // true (coerced)
console.log(value === 1); // false (string vs number)

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Equality Operators in JavaScript

In this video, I explain how equality works in JavaScript. You'll learn the difference between == and ===, why type coercion can lead to unexpected results, and why it's best to use strict equality. Perfect for avoiding common beginner mistakes with comparisons in JavaScript.

5m 45s