JavaScript Comparisons

Understanding comparison operators and equality in JavaScript

⚖️ What are JavaScript Comparisons?

Comparison operators are used to compare two values and return a boolean result (true or false). They are essential for making decisions in your code. 


// Basic comparison example
let age = 18;
let isAdult = age >= 18;
console.log(isAdult); // true

Output:

true

Comparison Operators

==

Equal To

Compares values (type conversion) 

5 == "5" // true
===

Strict Equal

Compares values and types 

5 === "5" // false
!=

Not Equal

Values are not equal 

5 != 3 // true
!==

Strict Not Equal

Values or types are not equal 

5 !== "5" // true

🔹 Relational Operators

These operators compare the relationship between values: 

let a = 10;
let b = 5;

console.log(a > b);   // true (greater than)
console.log(a < b);   // false (less than)
console.log(a >= 10); // true (greater than or equal)
console.log(b <= 5);  // true (less than or equal)

Output:

true

false

true

true

🔹 String Comparisons

JavaScript can compare strings alphabetically: 

let name1 = "Alice";
let name2 = "Bob";

console.log(name1 < name2);  // true (A comes before B)
console.log("apple" > "Banana"); // true (lowercase > uppercase)

// Case-insensitive comparison
let fruit1 = "apple";
let fruit2 = "APPLE";
console.log(fruit1.toLowerCase() === fruit2.toLowerCase()); // true

Output:

true

true

true

🔹 Practical Examples

Real-world usage of comparison operators: 

// Age verification
let userAge = 16;
let canVote = userAge >= 18;
console.log("Can vote:", canVote);

// Grade evaluation
let score = 85;
let grade = score >= 90 ? "A" : score >= 80 ? "B" : "C";
console.log("Grade:", grade);

// Password strength
let password = "mypass123";
let isStrong = password.length >= 8;
console.log("Strong password:", isStrong);

Output:

Can vote: false

Grade: B

Strong password: true

🧠 Test Your Knowledge

What does 5 === "5" return?