Math

Using numbers, number operators, and math functions.

Numeric values: 0, 1, 2, 6.7, 10.083…

Just numbers by themselves. Sometimes these are called numeric literals.

Integers: whole numbers

let num = 0;
num = 0;
num = 1;
num = 2;

Floating point: numbers with a fractional part

Numbers can have their fractional part too. The decimal point is between the digits of the number. But, floating point numbers have the decimal point at any spot between digits, like: 3.14159 or 651.75.

let num = 0
num = 6.7
num = 10.083

Arithmetic binary operation (+, -, *, /)

The operations for basic arithmetic: add, subtract, multiply, and divide.

let more = 0+1;
let less = 0-1;
let twice = 1*2;
let divide = 8/4;

Remainder (%)

This is a extra operator for division. You can find out how much is left over if one number doesn’t divide into the other number evenly.

We know that 4 / 2 = 2, so 2 divides into 4 evenly. But, 5 / 2 = 2 with a remainder of 1. So, the remainder operation, 5 % 2 = 1, gives the number that’s left over from a division operation.

let remainder = 7%4;

Exponent (**)

The exponent operator will multiply the number on the left by itself for the amount of times of the number on its right. That is, 4 ** 2 = 4 * 4 and 2 ** 3 = 2 * 2 * 2. The area of a square that has sides with a length of 5 is equal to one side multiplied by another. For a square, all sides are equal, so:

let side = 5;
let area = side * side;

But using the exponent operator, this is the same as:

let side = 5;
let area = side ** 2;

The volume of a cube is three sides multiplied together. The two volumes are the same:

let side = 5;
let volume1 = side * side * side;
let volume2 = side ** 3;

Square root

The square root of a number is another number that when multiplied by itself it becomes the original number. You know that 2 * 2 equals 4 so the square root of 4 is 2. It’s called a square root because the area of a square is the length of two equal sides multplied together. The root is the length of a side.

let side = 5
let square = side * side
let root = Math.sqrt(side)

Absolute value

When you want to know how much a number is without its sign (+/-). The absolute value of -5 is 5 and the absolute value of 5 is also 5. The absolute value is sometimes called the magnitude.

let item = Math.abs(-5);

Minimum and maximum of two values

You can get the smaller or the bigger of two numbers with the min and max functions.

  • The minimum of 2 and 9: Math.min(2, 9) equals 2.
  • The maximum of 3 and 9: Math.max(3, 9) equals 9.
let minval = Math.min(0, 1);
let maxval = Math.max(8, 2);

Random value

Make up any number from a minimum value to a some maximum value. If you want a random number up to 100, say: Math.randomRange(0, 100).

let myRandom = Math.randomRange(0, 5);

See also

abs, min, max, randomRange