Number Methods

Number methods help you shape and check numbers.

You can round them, fix decimals, or test if a value is safe.

Think of measuring cups and rulers for numbers.

toFixed

toFixed makes a string with a set number of decimals.

Handy for money style display.

toString

toString turns a number into text.

You can even pick another base, like binary.

Math.round, floor, ceil

These live on Math, but they work with numbers every day.

round goes to nearest. floor goes down. ceil goes up.

Number.isNaN

Number.isNaN checks for NaN carefully.

Number.isFinite

This asks if a value is a normal finite number.

Infinity and NaN fail the test.

parseFloat

parseFloat reads a decimal number from the start of a string.

Tip: Remember toFixed returns a string. Convert back with Number if you need more math.