How can I create a 2d array in javascript and load it with the values from user input?
var b;
b = new Array( 3 ); // allocate rows
b[ 0 ] = new Array( 3 ); // allocate columns for row 0
b[ 1 ] = new Array( 3 ); // allocate columns for row 1
b[2]= new Array(3);
How to create a 2D array: How can I create a two dimensional array in JavaScript?
Loading values from user input: essentially use
b[0][0] = myInput00;
b[0][1] = myInput01;
...etc. etc.
It may be more structured to use for-loops, i.e.
for (var i=0;i<input.length;i++)
{
for (var j = 0; j < input.height; j++)
{
b[i][j] = input[i][j];
}
}
with input[i][j] replaced with however your input is formatted. The answer clearly varies slightly depending on the input format, but that's the general pattern.
Edit: if the input is a fixed 3x3 box, you might just assign all the table cells as individual divs or spans, and allocate each of the array indices (b[0][0], b[0][1] etc.) in turn.
Multi-dimensional arrays in many languages are just arrays within arrays.
// Create an array with 4 elements.
var b = [1, [2, 3], [4, [5, 6], 7], 8];
console.log(b.length); // 4
// Looping through arrays
for(var i=0; i<b.length; i++){
// b[0] = 1
// b[1] = [2, 3]
// b[2] = [4, Array[2], 7]
// b[3] = 8
console.log("b["+i+"] =", b[i]);
}
// Since b[1] is an array, ...
console.log(b[1][0]); // First element in [2, 3], which is 2
// We can go deeper.
console.log(b[2][1]); // [5, 6]
console.log(b[2][1][0]); // 5
// We can change entries, of course.
b[2][1][0] = 42;
console.log(b[2][1][0]); // 42
b[1] = ['a', 'b', 'c'];
console.log(b[1][0]); // "a"
Therefore, making a 3 by 3 matrix can be done like this:
var b = [];
for(var i=0; i<3; i++){
b[i] = [];
for(var j=0; j<3; j++){
b[i][j] = prompt("b["+(i+1)+","+(j+1)+"] = ?");
}
}
(Of course, this is not the best way to do, but it is the easiest way to follow.)
prompt("Please enter your name","");. In fact you already created a 2D array in your code. -- See also: stackoverflow.com/questions/966225/…