Before we dive into the specifics of manipulating 2D arrays, let's quickly review what they are. A 2D array, also known as a matrix, is an array of arrays. It's a data structure that stores data in a tabular form, with rows and columns. Each element in a 2D array is identified by its row and column index.
var myArray = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]; var value = myArray[1][2]; // value = 6 Modifying an element in a 2D array is similar to accessing an element. You simply assign a new value to the element using its row and column index. Codehs 8.1.5 Manipulating 2d Arrays
var myArray = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]; for (var i = 0; i < myArray.length; i++) { myArray[i].splice(1, 1); } // myArray = [[1, 3], [4, 6], [7, 9]]; Before we dive into the specifics of manipulating
var myArray = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]; myArray[1][2] = 10; // myArray = [[1, 2, 3], [4, 5, 10], [7, 8, 9]]; Adding a new row to a 2D array can be done using the push() method. Each element in a 2D array is identified
var arrayName = [[value1, value2, ...], [value3, value4, ...], ...]; For example:
for (var i = 0; i < arrayName.length; i++) { arrayName[i].splice(columnIndex, 1); } For example: