JavaScript Multidimensional Array
Multidimensional arrays are not directly provided in JavaScript. If we want to use anything which acts as a multidimensional array then we need to create a multidimensional array by using another one-dimensional array. So multidimensional arrays in JavaScript is known as arrays inside another array. We need to put some arrays inside an array, then the total thing is working like a multidimensional array. The array, in which the other arrays are going to insert, that array is use as the multidimensional array in our code. To define a multidimensional array its exactly the same as defining a normal one-dimensional array.
One-Dimensional array:
let arr = []; // Empty 1D array
let arr1 = ["A", "B", "C", "D"] // 1D array contains some alphabets
let arr1 = [1, 2, 3, 4, 5] // 1D array contains some digits
Multidimensional-Dimensional array:
Method 1:
1st, need to define some 1D array
let arr1 = ["ABC", 24, 18000];
let arr2 = ["EFG", 30, 30000];
let arr3 = ["IJK", 28, 41000];
let arr4 = ["EFG", 31, 28000];
let arr5 = ["EFG", 29, 35000];
// "salary" defines like a 1D array but it already contains some 1D array
let salary = [arr1, arr2, arr3, arr4, arr5];
Here arr1, arr2, …arr5 are some 1D arrays that are inside the salary array.
Method 2:
let salary = [
["ABC", 24, 18000],
["EFG", 30, 30000],
["IJK", 28, 41000],
["EFG", 31, 28000],
];
Here, the salary array works like a multidimensional array. This notations are known as array literals.
Accessing the element of the salary array:
- To access the array element we need a simple index-based notation
// This notation access the salary of "ABC" person which is 18000,
// [0] selects 1st row, and [2] selects the 3rd element
// of that 1st row which is 18000
salary[0][2];
// Similarly,
salary[3][2]; // Selects 28000
**This notation is used for both Method 1 and Method 2.
- For many iteration, we need to use loop to access the elements,
// This loop is for outer array
for (let i = 0, l1 = salary.length; i < l1; i++) {
// This loop is for inner-arrays
for (let j = 0, l2 = salary[i].length; j < l2; j++) {
// Accessing each elements of inner-array
documents.write( salary[i][j] );
}
}
Adding elements in Multidimensional Array: Adding elements in multi-dimensional arrays can be achieved in two ways in inner array or outer array. The inner array can be done in two different ways.
- Adding elements to inner array:
- We can use simple square bracket notation to add elements in multidimensional array.
salary[3][3] = "India";
// It adds "India" at the 4th index of 4th sub-array,
// If we print the entire 4th sub-array, document.write(salary[3]);
// the output will be : ["EFG", 31, 28000, "India"]
// indexing starts from 0
- We can use push() method to add elements in the array.
salary[3].push("India", "Mumbai");
// It add "India" at the 4th index and "Mumbai" at
// 5th index of 4th sub-array
// If we print the entire 4th sub-array,
// document.write(salary[3]);
// The output will be : ["EFG", 31, 28000, "India", "Mumbai"]
// Indexing starts from 0
- Adding elements to outer array: It is much similar to previous methods.
salary.push(["MNO", 29, 33300]);
// This row added after the last row in the "salary" array
Removing elements in Multidimensional Array: We can use pop() methods to remove elements from inner-arrays, and also use pop() method for removing a entire inner array.
// Remove last element from 4th sub-array
// That is 28000 indexing starts from 0
salary[3].pop();
// Removes last sub-array
// That is "["EFG", 31, 28000]"
salary.pop();
Example 1: Below is the example
javascript
// Prints a simple multidimensional array in JavaScript let arr1 = [ "ABC" , 24, 18000]; let arr2 = [ "EFG" , 30, 30000]; let arr3 = [ "IJK" , 28, 41000]; let arr4 = [ "EFG" , 31, 28000]; let arr5 = [ "EFG" , 29, 35000]; let salary = [arr1, arr2, arr3, arr4, arr5]; for (let i = 0; i < salary.length; i++) { console.log(salary[i]); } |
[ 'ABC', 24, 18000 ] [ 'EFG', 30, 30000 ] [ 'IJK', 28, 41000 ] [ 'EFG', 31, 28000 ] [ 'EFG', 29, 35000 ]
Example 2: Below is the example.
javascript
// Prints a simple multidimensional array in // JavaScript with different declaration let salary = [ [ "ABC" , 24, 18000], [ "EFG" , 30, 30000], [ "IJK" , 28, 41000], [ "EFG" , 31, 28000], ]; for (let i = 0; i < salary.length; i++) { console.log(salary[i]); } |
[ 'ABC', 24, 18000 ] [ 'EFG', 30, 30000 ] [ 'IJK', 28, 41000 ] [ 'EFG', 31, 28000 ]
Example 3: Below is the example.
javascript
// Prints a simple multidimensional array in JavaScript // where we just print the salary of a specific person let salary = [ [ "ABC" , 24, 18000], [ "EFG" , 30, 30000], [ "IJK" , 28, 41000], [ "EFG" , 31, 28000], ]; console.log( "salary of 2nd person : " + salary[1][2]); console.log( "salary of 4th person : " + salary[3][2]); |
salary of 2nd person : 30000 salary of 4th person : 28000
Example 4: Below is the example.
javascript
// Prints a simple multidimensional array in // JavaScript where we add elements in the array // using simple square bracket and push() method let salary = [ [ "ABC" , 24, 18000], [ "EFG" , 30, 30000], [ "IJK" , 28, 41000], [ "EFG" , 31, 28000], ]; // Prints first array console.log( "Original array :<br>" ); for (let i = 0; i < salary.length; i++) { console.log(salary[i]); } // Adding "India" at the 4th index of 4th sub array salary[3][3] = "India" ; console.log( "<br>after adding \"India\" at the 4th array :<br>" ); for (let i = 0; i < salary.length; i++) { console.log(salary[i]); } console.log( "<br>after adding \"USA\" and \"Canada\" " + "at the 3rd array using \"push()\" method :" ); salary[2].push( "USA" , "Canada" ); // Adding "USA" and "Canada" in the 2nd sub-array for (let i = 0; i < salary.length; i++) { console.log(salary[i]); } |
Output:
Original array :
ABC, 24, 18000
EFG, 30, 30000
IJK, 28, 41000
EFG, 31, 28000
after adding "India" at the 4th array :
ABC, 24, 18000
EFG, 30, 30000
IJK, 28, 41000
EFG, 31, 28000, India
after adding "USA" and "Canada" at the 3rd array using "push()" method :
ABC, 24, 18000
EFG, 30, 30000
IJK, 28, 41000, USA, Canada
EFG, 31, 28000, India
Example 5: Below is the example.
javascript
// Prints a simple multidimensional array in // JavaScript where we add a new inner array let salary = [ [ "ABC" , 24, 18000], [ "EFG" , 30, 30000], [ "IJK" , 28, 41000], [ "EFG" , 31, 28000], ]; // Prints first array console.log( "Original array :" ); for (let i = 0; i < salary.length; i++) { console.log(salary[i]); } console.log( "After adding a new inner array :" ); // Pushing a new sub-array salary.push([ "MNO" , 29, 33300]); for (let i = 0; i < salary.length; i++) { console.log(salary[i]); } |
Original array : [ 'ABC', 24, 18000 ] [ 'EFG', 30, 30000 ] [ 'IJK', 28, 41000 ] [ 'EFG', 31, 28000 ] After adding a new inner array : [ 'ABC', 24, 18000 ] [ 'EFG', 30, 30000 ] [ 'IJK', 28, 41000 ] [ '...
Output:
Original array :
ABC, 24, 18000
EFG, 30, 30000
IJK, 28, 41000
EFG, 31, 28000
After adding a new inner array :
ABC, 24, 18000
EFG, 30, 30000
IJK, 28, 41000
EFG, 31, 28000
MNO, 29, 33300
Example 6: Below is the example.
javascript
// Prints a simple multidimensional array in // JavaScript where we remove a single element // and a entire sub-array let salary = [ [ "ABC" , 24, 18000], [ "EFG" , 30, 30000], [ "IJK" , 28, 41000], [ "EFG" , 31, 28000], ]; // Prints first array console.log( "Original array :" ); for (let i = 0; i < salary.length; i++) { console.log(salary[i]); } console.log( "After removing last element " + "of last inner array :" ); // Removes the last element of 3rd sub-array salary[3].pop(); for (let i = 0; i < salary.length; i++) { console.log(salary[i] + "" ); } console.log( "After removing last inner array :" ); // Removes last sub-array salary.pop(); for (let i = 0; i < salary.length; i++) { console.log(salary[i]); } |
Original array : [ 'ABC', 24, 18000 ] [ 'EFG', 30, 30000 ] [ 'IJK', 28, 41000 ] [ 'EFG', 31, 28000 ] After removing last element of last inner array : ABC,24,18000 EFG,30,30000 IJK,28,41000 EFG,31 Aft...
JavaScript is best known for web page development but it is also used in a variety of non-browser environments. You can learn JavaScript from the ground up by following this JavaScript Tutorial and JavaScript Examples.
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