New Array ()
New Array (len)
New Array ([item0,[item1,[item2,...]]]
Methods for using Array objects:
var objarray=new Array ();
Objarray.concact ([item1[,item2[,....]]] -------------------The argument list is connected to the back of the Objarray to form a new array and returns, the original array is unaffected. such as: Var arr=["A", "B", "C"];
Arr.concact ("D", "E");
An array that includes the letter elements from "a" to "E" is returned. And the arr itself is unaffected.
Objarray.join (separator)-----------------converts the array to a string with the character specified separator as a delimiter, and the same as ToString () when the seperator is a comma.
Objarray.pop ()---------Popular, is the last element that pops up the array. Combining the following push method makes it possible to use an array as a stack. The Pop method returns the value of the last element of the array, and the length property is reduced by 1, which means that the last element is lost immediately after the return.
Objarray.push ([value1[,value2[,....]]) -------------adds a parameter to the end of the array. For example: [1,2,3, 4].push ("A", "B") will get [1,2,3,4, "A", "B"]
Objarray.reverse () Reverses the elements in the array. For example: [1,2,3].reverse () will get [3,2,1], which is done on the existing array, and returns the array itself.
The Objarray.shift ()-----------removes the first element of the array and returns the value of the element. The nature of this method is similar to the Pop method, and the pop method is to remove the last element.
The Objarray.slice (start,end)-----------returns a subset of the array objects, starting at start (including start), ending with end (excluding ends), and not affected by the existing array. For example: [1,2,3,4,5,6].slice (1,4) will get [2,3,4]. When start or end is negative, use them plus the value after the length. For example: [1,2,3,4,5,6].slice ( -4,-1) will get [3,4,5]. If end is less than or equal to start, an empty array is returned.
Objarray.sort (comparefn)-------sorts an array based on the size comparison function defined by Comparefn. Function Comparefn must accept two parameters Element1,element2, if needed element1 row before Element2, should return a negative number, if you need element1 row after Element2, should return a positive number, Returns 0 if two numbers are treated equally (that is, to keep the original order). When COMPAREFN is omitted, the elements are arranged in a dictionary order. For example, the comparison function defined is cmp:function CMP (e1,e2) {return e1-e2;} Then [3,4,2,7].sort (CMP) will get [2,3,4,7].
Objarray.splice (start,deletecount[,item1,item2[,...]]) This is a complex function that completes the deletion, substitution, and insertion of array elements. Where the start parameter represents the index position to operate, deletecount refers to the number of elements (including the start position) of the element to be deleted from start, or, if DeleteCount omitted, to remove the remainder of the array from start. [, item1[,item2[,...]]] Represents an optional list of elements inserted before start. Such as:
var arr=[0,1,2,3,4,5,6];
Arr.splice (1,1);
document.write (arr)//show "0,2,3,4,5,6"
arr=[0,1,2,3,4,5,6];
Arr.splice (0,0, "a", "B");
document.write (arr)//show "a,b,0,1,2,3,4,5,6"
arr=[0,1,2,3,4,5,6];
Arr.splice (3,2, "C", "D");
document.write (arr)//show "0,1,2,c,d,5,6"
Objarray.unshift (item1[,item2[,...]]) -------------------Inserts the argument list at the beginning of the array. Its nature and the type of the push method, but the push method is to add the element to the end of the array. For example: [1,2,3,4].unshift ("A", "B") will be given ["a", "B", 1,2,3,4].
JS array elements to add and delete has been more puzzled, today finally found the details of the information, first to give me the test code-^
var arr = new Array ();
Arr[0] = "AAA";
ARR[1] = "BBB";
ARR[2] = "CCC";
alert (arr.length);//3
Arr.pop ();
alert (arr.length);//2
Alert (arr[arr.length-1]);//bbb
Arr.pop ();
Alert (arr[arr.length-1]);//aaa
alert (arr.length);//1
var arr2 = new Array ();
alert (arr2.length);//0
Arr2[0] = "AAA";
ARR2[1] = "BBB";
alert (arr2.length);//2
Arr2.pop ();
alert (arr2.length);//1
ARR2 = Arr2.slice (0,arr2.length-1);
alert (arr2.length);//0
Arr2[0] = "AAA";
ARR2[1] = "BBB";
ARR2[2] = "CCC";
ARR2 = Arr2.slice (0,1);
alert (arr2.length);//1
Alert (arr2[0]);//aaa
Alert (arr2[1]);//undefined
Shift: Deletes the first item of the original array and returns the value of the deleted element, or returns undefined if the array is empty
var a = [1,2,3,4,5];
var B = A.shift (); a:[2,3,4,5] B:1
Unshift: Adds a parameter to the beginning of the original array and returns the length of the array
var a = [1,2,3,4,5];
var B = A.unshift ( -2,-1); a:[-2,-1,1,2,3,4,5] B:7
Note: The test return value under IE6.0 is always undefined,ff2.0 the test return value is 7, so the return value of this method is unreliable, and it is necessary to use splice instead of this method with the return value.
Pop: Deletes the last item of the original array and returns the value of the deleted element, or returns undefined if the array is empty
var a = [1,2,3,4,5];
var B = A.pop (); a:[1,2,3,4] b:5//can be called directly without the return of the word.
Push: Adds a parameter to the end of the original array and returns the length of the array
var a = [1,2,3,4,5];
var B = A.push (6,7); a:[1,2,3,4,5,6,7] B:7
Concat: Returns a new array that adds a parameter to the original array.
var a = [1,2,3,4,5];
var B = A.concat (6,7); a:[1,2,3,4,5] b:[1,2,3,4,5,6,7]
Splice (Start,deletecount,val1,val2,...) : Deletes the DeleteCount entry from the start position and inserts the Val1,val2 from that location,...
When you empty an array, you simply pass the startindex.
If you do not delete all elements, then pass the DeleteCount parameter.
Splice also has to delete after the addition of the function, that is, delete a few elements, and then add a number of elements in the deletion, delete and add the number of elements do not have to equal, then Hou DeleteCount also want to use.
var a = [1,2,3,4,5];
var B = A.splice (2,2,7,8,9); a:[1,2,7,8,9,5] b:[3,4]
var B = a.splice (0,1); With shift
A.splice (0,0,-2,-1); var B = a.length;//with Unshift
var B = A.splice (a.length-1,1);//Same pop
A.splice (a.length,0,6,7); var B = a.length; Same push
Reverse: Reverse-order the array
var a = [1,2,3,4,5];
var B = A.reverse (); a:[5,4,3,2,1] b:[5,4,3,2,1]
Sort (orderfunction): Sorting by specified array of parameters
var a = [1,2,3,4,5];
var B = A.sort (); a:[1,2,3,4,5] b:[1,2,3,4,5]
Slice (Start,end): Returns a new array of items from the original array specifying the start subscript to the end subscript
var a = [1,2,3,4,5];
var B = a.slice (2,5); a:[1,2,3,4,5] b:[3,4,5]
Join (Separator): Sets the element of an array to a string, separator as a delimiter, and omitted by default with a comma as the delimiter
var a = [1,2,3,4,5];
var B = A.join ("|"); a:[1,2,3,4,5] B: "1|2|3|4|5"
Then give an array to simulate the Javastringbuffer processing string method:
Copy Code code as follows:
/**
* String handler function
*/
function StringBuffer () {
var arr = new Array;
This.append = function (str) {
Arr[arr.length] = str;
};
this.tostring = function () {
Return Arr.join ("");//ping append incoming array into a string
};
}
Today, a join is suddenly found in applications as a good way to convert an array into a string, so it is encapsulated as an object using:
Copy Code code as follows:
/**
* Converts an array into a string that is separated by a particular symbol
*/
function arraytostring (arr,separator) {
if (!separator) separator = "";//separator null defaults to NULL
return Arr.join (separator);
}
/**
* Find the string contained in the array
*/
function arrayfindstring (arr,string) {
var str = arr.join ("");
return Str.indexof (String);
}
