Devlog - 2025-10-26

🚀 What I Did

🧠 What I Learned

NaN - Not a number.

let result = 0 / 0;
console.log(result); // Output: NaN

isNaN - used to find if it is NaN or not.

console.log(isNaN(NaN));       // true
console.log(isNaN(undefined)); // true
console.log(isNaN({}));        // true

console.log(isNaN(true));      // false
console.log(isNaN(null));      // false
console.log(isNaN(37));        // false

console.log(isNaN("37"));      // false: "37" is converted to 37
console.log(isNaN("37.37"));   // false: "37.37" is converted to 37.37
console.log(isNaN(""));        // false: empty string is converted to 0
console.log(isNaN(" "));       // false: string with a space is converted to 0

console.log(isNaN("blabla"));  // true: "blabla" is not a number

parseFloat() and parseInt() are two essential methods in JavaScript for converting strings to numbers.
.toFixed() method is a built-in JavaScript function that formats a number using fixed-point notation.

console.log((3.14159).toFixed(3));  // Output: "3.142"
console.log((3.14449).toFixed(3));  // Output: "3.144"
console.log((3.14550).toFixed(3));  // Output: "3.146"

🔥 What’s Next

Functions.

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