JavaScript Math Object

Math.PI This value is approximately 3.141592653589793.

Math.ceil (x) rounding up

Math.floor (x) rounding down

Math.pow (x, y) returns the Y power of X (Note: If the result is an imaginary or negative number, the method returns NaN.) If a floating-point overflow is caused by an exponent that is too large, the method returns Infinity. ）

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Note: The Math object is not a class of objects like Date and String, so there is no constructor for math (), a function like Math.sin () is just a function, not a method of an object. You do not have to create it, and you can invoke all of its properties and methods by using Math as an object.

Via http://www.w3school.com.cn/jsref/jsref_obj_math.asp

JavaScript Math Object