JS Math function

1. Discard the fractional part, preserving the whole number of parts
parseint (5/2)

2. Rounding up, with decimals on the integer part plus 1

Math.ceil (5/2)

3, rounded.

Math.Round (5/2)

4, rounding down

Math.floor (5/2)

Math Object Properties

Properties	Description
E	Returns the arithmetic constant E, which is the base of the natural logarithm (approximately equal to 2.718).
LN2	Returns the natural logarithm of 2 (approximately equal to 0.693).
LN10	Returns the natural logarithm of 10 (approximately equal to 2.302).
Log2e	Returns the logarithm of E with a base of 2 (approximately equal to 1.414).
log10e	Returns the logarithm of E with a base of 10 (approximately equal to 0.434).
Pi	Returns the Pi (approximately equal to 3.14159).
Sqrt1_2	Returns the reciprocal of the square root that returns 2 (approximately equals 0.707).
SQRT2	Returns the square root of 2 (approximately equal to 1.414).

Math Object method

Method	Description
ABS (x)	The absolute value of the return number.
ACOs (x)	The inverse cosine value of the returned number.
ASIN (x)	Returns the inverse chord value of the number.
Atan (x)	Returns the inverse tangent of x with a value between-PI/2 and PI/2 radians.
ATAN2 (y,x)	Returns the angle from the x-axis to the point (X, y) (between-PI/2 and PI/2 radians).
Ceil (x)	The logarithm is rounded up.
COS (x)	The cosine of the returned number.
EXP (x)	Returns the exponent of E.
Floor (x)	The logarithm is rounded down.
Log (x)	Returns the natural logarithm of the number (bottom is e).
Max (x, y)	Returns the highest value in X and Y.
Min (x, y)	Returns the lowest value in X and Y.
Pow (x, y)	Returns the Y power of X.
Random ()	Returns a random number between 0 and 1.
Round (x)	Rounds the number to the nearest integer.
Sin (x)	Returns the sine of a number.
sqrt (x)	Returns the square root of the number.
Tan (x)	Returns the tangent of a corner.
Tosource ()	Returns the source code for the object.
ValueOf ()	Returns the original value of the Math object.

JS Math function