Js--string, Date, Array object

/*
* String Object
Property length
Method
*/
The length property of the string
var StrL = "ABCDE";
document.write ("<br/>");
document.write ("attribute:" + strl.length);
Method of String
document.write ("<br/>");
document.write ("Method:" + strl.bold ());
document.write ("<br/>");
document.write (Strl.fontcolor ("Red"));
document.write ("<br/>");
document.write (Strl.fontsize (7));
document.write ("<br/>");
Sub sup subscript

document.write ("<br/>");
var str1 = "Hello";
var str2 = "World";
document.write ("String link:" + str1.concat (str2));
document.write ("<br/>");
document.write ("returns the specified position string, where no value returns null:" + str2.charat (0));
document.write ("<br/>");
document.write ("Returns the index of the specified position string, the value does not return-1:" + str2.indexof ("w"));
document.write ("<br/>");
var str3 = "a-b-c-d";
var arr1 = Str3.split ("-");
document.write ("Split method Cut, slice string, array:" + arr1.length);
document.write ("<br/>");
var STR4 = "ABCD";
document.write ("Replace replace, replacing a with E" + str4.replace ("A", "E"));
document.write ("<br/>");
document.write ("substr," + str4.substr (1, 2)),//BC 2-bit backward from 1th position
document.write ("<br/>");
document.write ("substring:" + str4.substring (1, 2)),//b from the beginning to the end of the first, does not contain the last person [

3 ways to create an array
var arr21 = [1, 2, 3];
var arr22 = new Array (3);
var arr23 = new Array (1, 2, 3);

/**js Array Object
concat ()
Join ()
push ()
Pop ()
reverse ()
*/
var arr11 = [1, 2, 3];
document.write (" document.write (arr11.length);
document.write ("<br/>");
document.write ("concat (): links to Arrays" + arr11.concat ());
document.write ("<br/>");
var arr12 = new Array (3);
Arr12[0] = "a";
Arr12[1] = "B";
Arr12[2] = "C";
document.write ("Join (): Splits an array with the specified character:" + Arr12.join ("-"));
document.write ("<br/>");
document.write ("push (): Adds an element at the end of the array and returns the new array length:" + Arr12.push ("D"));
document.write ("<br/>");
var arr13 = ["AAA", "BBB", "CCC"];
var arr14 = ["www", "QQQ"];
document.write ("Add an array with the push method in an array:" + Arr13.push (arr14));
document.write ("<br/>");
//Use push to add an array to the array, and he will add the array as a string to the array
for (var i = 0; i < arr13.length; i++) {
document.write (arr13[ I]);
document.write ("<br/>");
}

document.write ("<br/>");
var arr14 = ["Zhangsan", "Lisi", "Wangwu", "Zhaoliu"];
document.write ("Old length:" + arr14.length);
document.write ("<br/>");
document.write ("Pop () deletes the last element, and returns the last element:" + arr14.pop ());
document.write ("<br/>");
document.write ("New length:" + arr14.length);
document.write ("<br/>");
document.write ("New arr:" + arr14);

document.write ("<br/>");
document.write ("reverse (): Reverses the order in the array:" + arr14.reverse ());

/**date Object
toLocaleString: Convert dates to custom date formats
getFullYear: Get the current four-digit year
GetMonth: Get the current month, the return value is 0月-November, get the value +1
GetDay: Gets the current week, the return value is 0-6, Sunday is 0 indicates
GetDate: Get the current day, 1-31
GetHours: Get the current hour
Getminutes (): Get the current minute
Getseconds (): Gets the current seconds
GetTime (): Gets the number of milliseconds: the number of milliseconds that are returned is 1970-1-1 to the present: effect of processing cache with milliseconds (no cache) Example: www.baidu.com? Number of milliseconds
*/
var date = new Date ();
document.write ("document.write ("Local date format:" + date);//Gets the current time
document.write ("<br/>");
document.write ("converted to a custom date format:" + date.tolocalestring ());
document.write ("<br/>");
document.write ("Get the current year's method: getFullYear ():" + date.getfullyear ());
document.write ("<br/>");
document.write ("method to get the current month: GetMonth ():" + (Date.getmonth () + 1));
document.write ("<br/>");
document.write ("Get the current Week: GetDay ():" + date.getday ());
document.write ("<br/>");
document.write ("Get Current day: GetDate ():" + date.getdate ());
document.write ("<br/>");
document.write ("Get Current Hour: getHours ():" + date.gethours ());
document.write ("<br/>");
document.write ("Get Current minute: getminutes ():" + date.getminutes ());
document.write ("<br/>");
document.write ("Get Current Seconds: getseconds ():" + date.getseconds ());
document.write ("<br/>");
document.write ("Get milliseconds: GetTime ()" + date.gettime ());//Returns the number of milliseconds since 1970-1-1. Application scenario: The effect of processing the cache with milliseconds (no cache) Example: Www.baidu.com? Number of milliseconds

The/**math object is full of static methods, using Math. Method Name ();
Ceil (): Rounding up
Floor (): Rounding Down
Round (): Rounding
Random (): Randomly number
Max (x, y): Maximum value
Min (x, y): Minimum value
Pow (x, y): Power of X,
*/
document.write ("var mm=10.4;
document.write ("Ceil (): Rounded up:" +math.ceil (mm));
document.write ("<br/>");
document.write ("Floor (): Round Down:" +math.floor (mm));
document.write ("<br/>");
document.write ("round () rounded" +math.round (mm));
document.write ("<br/>");
document.write ("Random () stochastic" +math.floor (Math.random () *10));//Get 0-9 random numbers
document.write ("<br/>");
document.write ("Pow (x, y): X's Y Power:" +math.pow (2,5));

Js--string, Date, Array object