A two-dimensional array of JS

Today, record the two-bit array of JS and attach an example.

I. The nature of a two-dimensional array: The elements in the array are also arrays.

In fact, we have all seen such a two-dimensional array, just don't care about it, for example:

var arr = [[[1,2,4,6],[2,4,7,8],[8,9,10,11],[9,12,13,15]]//This is a two-bit array
ARR[2][3]; 11 Note: Represents the element that contains the 4th row of the third column. Angle label starting from 0

Two. The following describes the initialization of a two-dimensional array

Remembering the nature of the two-dimensional array, initialization is hard for us. Take a look at the example

Example one:

var arr = [[1,2],[a,b]]; Alert (arr[1][0]); element of row 1th of column A 2nd

Example two:

Declaration of an instance 3:2-dimensional array:

var arr = new Array ();         First declare one-dimensional        for (Var i=0;i<5;i++) {          //one-dimensional length of 5           arr[i]=new Array ();    In the declaration two-dimensional           for (Var j=0;j<5;j++) {      //two-D length is 5              arr[i][j]=1;        

Then, traverse the two-dimensional array arr

for (Var i=0;i<arr.length;i++) {for (Var j=0;j<arr[i].length;j++) {document.write (arr[i][j]);  } document.write ("<br/>"); Results

Note: We write a newline that is written to the label because Document.Write () is written to the HTML document. So writing a newline cannot be "\ n".

Example: In a two-dimensional array, each row is ordered in ascending order from left to right, and each column is sorted in ascending order from top to bottom. Complete a function, enter such a two-dimensional array and an integer to determine if the array contains the integer

var arr = [[1,2,4,6],[2,4,7,8],[8,9,10,11],[9,12,13,15]];    Rule: First select the number in the upper-right corner of the array, if the number = the number to look for, the search process is finished, if the number > to find the number, exclude the column in which the number is located;//If the number < The number to find, reject the line where the number is located.            function Find (Arr,num) {if (num==undefined) {Console.log (num+ "is null");        Return            } while (num!=undefined&&arr.length) {var temp = arr[arr.length-1][0];                if (num = = temp) {Console.log (num+ "is finded");            return temp;                }else if (temp>num) {arr.pop ();                    if (arr.length = = 1) {console.log (num + "is NOT exists," +num+ "was less the MinValue");                Return                        }}else{for (Var i=0;i<arr.length;i++) {if (Arr[i].length ==1) {                        Console.log (num + "is NOT exists," +num+ "are more than the MaxValue");                    Return        } arr[i].shift ();        }}}} var result = find (arr,undefined); Console.log (result);

　　

　

　

　　

A two-dimensional array of JS