Type Coercion and Conversion

Type coercion is the automatic or implicit conversion of values from one data type to another (e.g., string to number). Type conversion (or casting) is the explicit conversion using functions like String(), Number(), Boolean().

Implicit coercion often happens with operators:

console.log("5" - 2); // 3 (string becomes number)
console.log("5" + 2); // '52' (number becomes string, concatenation)
console.log(true + 1); // 2 (true becomes 1)

Explicit conversion:

let str = "123";
let num = Number(str); // 123
let bool = Boolean(str); // true
let float = parseFloat("3.14"); // 3.14
let int = parseInt("10px"); // 10

Truthy and falsy: Values that coerce to false in boolean contexts: false, 0, ”, null, undefined, NaN. Everything else is truthy.

Comparison quirks:

Loose equality (==) performs type coercion.

Strict equality (===) does not.

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

Best practice: Use strict equality (===) and explicit conversions to avoid surprises.