A array which has got different number of elements in each row is calle as “Jagged “ Array. It is similar to normal 2D array but the only diference is number of elements in each row
Example for Normal Array
int[][] array1= {{1,2,3},{5,3,7},{7,5,4}}
Here we can see array1 is an example for Normal array as each row contains same number of elements or coloumns
first row contains 3 elements
second row constains 3 elements
third row contains 3 elements
Overall we say it’s a normal 2D array as all rows contain same number of elements
JAVA Code for NORMAL Array
package arrayproblems;
class Problem24 {
public static void main(String[] args) {
int[][] array2= {{1,2},{3,4}}; // normal 2D array
// iterating through elements of array
for(int i=0;i<array2.length;i++) {
for(int j=0;j<array2.length;j++) {
System.out.print(array2[i][j]+" ");
}
System.out.println();
}
}
}
In above code we can observe that the array2 contains 2 row’s, each row contains 2 elements. so we are using two for loops to iterate through elements of array
Example for Jagged Array
int[][] array2={{1,2},{2,3,4},{5,7,3,2,1}}
In array2 we can see that first row contains only 2 elements ,
second row contains 3 elements
third row constains 5 elements
Overall we can observe that each row is having diferent number of elements or coloumns so it is an example for “Jagged array”.
JAVA Code for JAGGED ARRAY
package arrayproblems;
class Problem24 {
public static void main(String[] args) {
int[][] array2= {{1,2,3},{2,2},{1,1,1,1,1},{4,8,2,2,2,3,2,3,2}};// jagged array 2D
for(int i=0;i<array2.length;i++) {
for(int j=0;j<array2[i].length;j++) {
System.out.print(array2[i][j]+" ");
}
System.out.println();
}
}
}
In above code we can see array2 has 4 rows of different length. first row contains 3 elements, second row contains 2 elements, third row contains 5 elements and fourth row contains 9 elements.
so overall number of elements are different in each row.
so we are using 2 for loops, first one for rows and second one for iterating the elements of each row.
NOTE: array2[i].length() will give how many elements are there in ith row
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