About the JS Date object mathematical object, the string object commonly used methods:

 
Common methods for String objects///////////////////////indexOf (), getting characters in a string The first occurrence of the position (from zero)//LastIndexOf (), the position of the last occurrence of the character in the string/var str = ' Helloword ';//var index = str.indexof (' o ');//var = s Tr.lastindexof (' h ');//Console.log (index),//Console.log (last),//Split (), split the string into an array by delimiter//parameter 1: delimiter, according to what delimiter to split// Parameter 2: Optional, limited to several elements//var str = ' www.baidu.com ';//var arr = str.split ('. '); /Console.log (arr);//replace (A, B) replaces a with b//var str = ' hellowordl1234 ';//var reg = ' 1234 ';//var result = Str.replace (Reg, ‘!‘);/ /Console.log (Result),//charat (index), looks for the character at index (//var str = ' hellow ');//var a = Str.charat (4);//4 index position character// Console.log (a);//Slice (start,end), intercept from start, intercept to end position/var str = ' Baidu ';//var result = Str.slice (0,2);// Console.log (result);//substr (start,length), intercept from start position, intercept length/var str = ' Qinghui ';//var result = Str.substr ( 0,4);//Console.log (Result),//toLowerCase (), convert string to lowercase//touppercase (), converts string to uppercase//var str = ' BaiDu ';//var upper = Str.touppercase ();//var lower = Str.tolowercase ();//Console.log (upper)//Console.log (lower); Common methods of mathematical objects//////////////////Math.Abs () Calculate absolute The value/var num = -100;//var result = Math.Abs (num),///Console.log (Result),//Math.ceil (), rounding up integers regardless of the number of decimals after the decimal point, will go into a whole//var  num = 123.001;//var result = Math.ceil (num);//Console.log (result);//Math.floor (), take integer down//var num = 123.99;//var result = Math.floor (num);//Console.log (Result),//Math.Round (), rounded rounding//var num = 123.4;//var result = Math.Round (num);//Cons Ole.log (result);//Math.max (), calculates the maximum//Math.min (), calculates the minimum value/var max = Math.max (100,200,220);//var min = math.min ( 100,200,220);//Console.log (max);//Console.log (min);//Math.pow (x, y) get X "power"//var result = Math.pow (2,3);// Console.log (result);//MATH.SQRT (NUM) obtains the square root of num/var result = math.sqrt (144);//Console.log (result);//Math.random () take A random number between 0-1//var random = Math.random ();//conSole.log (random); Date Object Common method//////////////////////Date object provides the following methods to obtain the month day, time division seconds: getFullYear, GetMonth (), GetDate (), getHours (), getminutes (), getseconds ()///Get Date object: new Date ()//var odate = new Date ( )////Get date, Time//var year = Odate.getfullyear ();//var month = Odate.getmonth () +1; The value is from 0-11 to see the number, 0 is January ...//month = month<Ten? ' 0 ' +month:month;//var day= Odate.getdate ();//var hour= Odate.gethours ();//var minute= Odate.getminutes ();//var second= Odate.getseconds ();//// write to Body in//document.write (' Current time: ' +year+ '-' +month+ '-' +day+ ' &nbsp;&nbsp;&nbsp; ' +hour+ ': ' +minute+ ': "+second)////getday () Get Day of the Week//var odate= newDate ();///Weekday//var week= Odate.getday ();//return value between 0-6, 0 for Sunday//Console.log (week),//toLocaleString (), convert Date object to cost time format//var odate= newDate ();//var a= Odate.tolocaledatestring ();//document.write (a);

Common methods of JS date objects, common methods of mathematical objects, common methods of String objects

About the JS Date object mathematical object, the string object commonly used methods: