Pre-requisites -
1. Post # 48 Arrays
2. Post # 92 'length' array attribute
Assuming that you have understood the array concepts from the above pre-requisite posts, I would like to explain how to use 'length' attribute to calculate the number of 2 dimensional arrays, rows and number of columns in a 3 dimensional array.
Example of a 2 dimensional array -
int a[][][] = new int[2][3][4];
Visual representation of the array -
To calculate the number of 2 dimensional arrays in this 3 dimensional array use -> a.length
To calculate the number of rows in the first 2 dimensional array of the 3 dimensional array use -> a[0].length
To calculate the number of columns in the first row of the first 2 dimensional array of the 3 dimensional array use -> a[0][0].length
To calculate the number of columns in the second row of the first 2 dimensional array of the 3 dimensional array use -> a[0][1].length
To calculate the number of columns in the third row of the first 2 dimensional array of the 3 dimensional array use -> a[0][2].length
To calculate the number of rows in the second 2 dimensional array of the 3 dimensional array use -> a[1].length
To calculate the number of columns in the first row of the second 2 dimensional array of the 3 dimensional array use -> a[1][0].length
To calculate the number of columns in the second row of the second 2 dimensional array of the 3 dimensional array use -> a[1][1].length
To calculate the number of columns in the third row of the second 2 dimensional array of the 3 dimensional array use -> a[1][2].length
Lets implement this on Eclipse IDE -
1. Launch Eclipse IDE, open Java Project 'Project 018' and create a new Java Class 'Class2' with main( ) method as shown below -
2. Write the following code to print arrays, rows and columns as shown below -
3. Run the java class 'Class2' and observe that the calculation got printed in the console as shown below -
This is how, we use the length attribute in a two dimensional array.
How to work with 'char' data type arrays will be explained in the next post.
Please comment below to feedback or ask questions.
'double' data type arrays will be explained in the next post.
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