.toString(16)
Number(value)
→ Converts a value to a number.console.log(Number("42")); // 42
console.log(Number("3.14")); // 3.14
console.log(Number("hello")); // NaN
Number.parseInt(string, radix?)
→ Converts a string into an integer.console.log(Number.parseInt("42")); // 42
console.log(Number.parseInt("101", 2)); // 5 (binary to decimal)
Number.parseFloat(string)
→ Converts a string into a floating-point number.console.log(Number.parseFloat("3.14")); // 3.14
Number.isInteger(value)
→ Checks if a value is an integer.console.log(Number.isInteger(10)); // true
console.log(Number.isInteger(10.5)); // false
Number.isNaN(value)
→ Checks if a value is NaN.console.log(Number.isNaN(NaN)); // true
console.log(Number.isNaN(10 / "a")); // true
console.log(Number.isNaN("hello")); // false
isFinite(value)
→ Checks if a value is a finite number.console.log(Number.isFinite(100)); // true
console.log(Number.isFinite(Infinity)); // false
console.log(Number.isFinite("100")); // false (not converted)
Number.toFixed(digits)
→ Formats a number to a fixed number of decimal places.let num = 3.14159;
console.log(num.toFixed(2)); // "3.14"
console.log((1.005).toFixed(2)); // "1.00" (watch out for floating-point precision issues)
Number.toPrecision(digits)
→ Formats a number to a specified precision.console.log((123.456).toPrecision(4)); // "123.5"