Math methodThe Math.Abs method returns the absolute value of the parameter values. Math.Abs (1)//1math.abs (-1)//1both the Math.max method and the Math.min method can accept multiple arguments, MATH.MAX returns the largest of them, Math.min returns the smallest parameter. Math.max (2,-1, 5)//5math.min (2,-1, 5)//-1The Math.floor method takes a parameter that returns the largest integer less than the parameter. Math.floor (3.2)//3math.floor (-3.2)//-4The Math.ceil method takes a parameter that returns the smallest integer greater than the parameter. Math.ceil (3.2)//4math.ceil (-3.2)//3 If you need a function that always returns a numeric integer part, you can implement it yourself. function Tointeger (x) {x = number (x); return x < 0? Math.ceil (x): Math.floor (x);} Tointeger (3.2)//3ToInteger (3.5)//3ToInteger (3.8)//3ToInteger ( -3.2)// -3tointeger ( -3.5)// -3tointeger (-3.8)//-3The Math.Round method is used for rounding. Math.Round (0.1)//0math.round (0.5)//1math.round (0.6)//1//equivalent to Math.floor (x + 0.5) Note that it handles negative numbers (mainly 0.5 processing). Math.Round ( -1.1)// -1math.round ( -1.5)// -1math.round (-1.6)//-2The Math.pow method returns an exponential value with the first argument as a base and the second argument to a power. Math.pow (2, 2)//4math.pow (2, 3)//8 The following is a method for calculating the area of a circle. var radius = 20;var Area = Math.PI * MATH.POW (RADIUS, 2);The Math.sqrt method returns the square root of the parameter value. If the argument is a negative value, Nan is returned. MATH.SQRT (4)//2MATH.SQRT ( -4)//NaNThe Math.log method returns the natural pair of values with E as the base. Math.log (MATH.E)//1Math.log (10)//2.302585092994046The Math.exp method returns the parameter of the constant E. Math.exp (1)//2.718281828459045MATH.EXP (3)//20.085536923187668 Math.random ()Math.random () returns a pseudo-random number from 0 to 1, which may be equal to 0, but must be less than 1. Math.random ()//0.7151307314634323random number generation functions of any range are as follows. function getrandomarbitrary (min, max) {return math.random () * (max-min) + min;} Getrandomarbitrary (1.5, 6.5)//2.4942810038223864random integer generation functions of any range are as follows. function Getrandomint (min, max) {return Math.floor (Math.random () * (Max-min + 1)) + min;} Getrandomint (1, 6)//5examples of returning random characters are as followsfunction Random_str (length) {var ALPHABET = ' abcdefghijklmnopqrstuvwxyz '; ALPHABET + = ' abcdefghijklmnopqrstuvwxyz '; ALPHABET + = ' 0123456789-_ '; var str = '; for (var i=0; i < length; ++i) {var rand = Math.floor (Math.random () * ALPHABET. length); str + = Alphabet.substring (rand, Rand + 1);} return str;} RANDOM_STR (6)//"Ndqkor" in the above code, the RANDOM_STR function takes an integer as an argument, returning a string of the specified length consisting of random characters within the variable alphabet. Trigonometric methods
Js-20170804-math Object
