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Language: Web
Expertise: Intermediate
Jan 21, 1999



Full Text Search: The Key to Better Natural Language Queries for NoSQL in Node.js

Two-Dimensional Arrays in JavaScript

Technically, JavaScript doesn't support multi-dimensional arrays, but you can simulate a two-dimensional array by creating an array of arrays. This can be particularly useful if you want to create a matrix of images or other objects on the screen. To create an array of arrays, create the "inner" arrays first and then use them to populate the "outer" array. The following JavaScript example creates a 5x5 matrix of rows and columns, similar to a game board.
columns1 = new Array(5);      
columns2 = new Array(5);   
columns3 = new Array(5);
columns4 = new Array(5);
columns5 = new Array(5);

rows = new Array(5);
rows[0] = columns1;
rows[1] = columns2;
rows[2] = columns3;
rows[3] = columns4;
rows[4] = columns5;

for (i=0; i < 5; i++) { columns1[i] = i; }           // number the columns 1 through 5
for (i=0; i < 5; i++) { columns2[i] = i + 5; }     // number the next row of columns 6 through 10
for (i=0; i < 5; i++) { columns3[i] = i + 10; }   // and so on
for (i=0; i < 5; i++) { columns4[i] = i + 15; }
for (i=0; i < 5; i++) { columns5[i] = i + 20; }
Now you can refer to any spot on the board by its x and y coordinates; rows[2][3] refers to spot number 14, three rows from the top and four from the left (because arrays begin numbering at zero).
Steve Renaker
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