JavaScript Numbers & Math

var pi = 3.141;
pi.toFixed(0);          # returns 3
pi.toFixed(2);          # returns 3.14 - for working with money
pi.toPrecision(2)       # returns 3.1
pi.valueOf();           # returns number
Number(true);           # converts to number
Number(new Date())      # milliseconds since 1970
parseInt("3 months");   # returns the first number: 3
parseFloat("3.5 days"); # returns 3.5
Number.MAX_VALUE        # largest possible JS number
Number.MIN_VALUE        # smallest possible JS number
Number.NEGATIVE_INFINITY# -Infinity
Number.POSITIVE_INFINITY# Infinity

var pi = Math.PI;       # 3.141592653589793
Math.round(4.4);        # = 4 - rounded
Math.round(4.5);        # = 5
Math.pow(2,8);          # = 256 - 2 to the power of 8
Math.sqrt(49);          # = 7 - square root
Math.abs(-3.14);        # = 3.14 - absolute, positive value
Math.ceil(3.14);        # = 4 - rounded up
Math.floor(3.99);       # = 3 - rounded down
Math.sin(0);            # = 0 - sine
Math.cos(Math.PI);      # OTHERS: tan,atan,asin,acos
Math.min(0, 3, -2, 2);  # = -2 - the lowest value
Math.max(0, 3, -2, 2);  # = 3 - the highest value
Math.log(1);            # = 0 natural logarithm
Math.exp(1);            # = 2.7182 pow(E,x)
Math.random();          # random number between 0 and 1
Math.floor(Math.random() * 5) + 1;  # random integer from 1 to 5

Math.E        # Euler's number
Math.PI       # PI
Math.SQRT2    # Square root of 2
Math.SQRT1_2  # Square root of 1/2
Math.LN2      # Natural log of 2
Math.LN10     # Natural log of 10
Math.LOG2E    # Base 2 log of E
Math.LOG10E   # Base 10 log of E