JS Tutorial

JavaScript Numbers

JavaScript numbers represent both integers and floating-point values using the same Number type. There is no separate type for integers and decimals — it's all just Number.

📌 Examples of Numbers

• Integer: let x = 10;
• Floating Point: let y = 3.14;
• Negative: let z = -5;

🧪 Try It Yourself:

Open your browser console and try the following code:

let a = 5;
let b = 2.5;

console.log(a + b);   // 7.5
console.log(a * b);   // 12.5
console.log(a / 0);   // Infinity
console.log("10" / 2); // 5 (automatic type conversion)
  

📐 Number Methods

• toFixed(n) → Rounds the number to n decimal places.
• toString() → Converts the number to a string.
• parseInt() → Parses a string and returns an integer.
• parseFloat() → Parses a string and returns a float.
• isNaN() → Checks if the value is NaN (Not-a-Number).

🔧 Live Example:

💡 Tips

• JavaScript automatically converts between number types when needed.
• Beware of floating point precision issues, e.g., 0.1 + 0.2 ≠ 0.3 exactly.
• Use Number.isNaN() to check for real NaN values.