null values keep appearing-CodePudding

I want to merge 2 Stirng arrays the first one is merged okay but the second one keeps having null values even though it isn't empty no errors just wrong values what is the problem here?

public class Q4 {
    public static void main(String[] args){
        String array1[] = new String[]{"Ahmad", "Adam"};
        String array2[] = new String[]{"Mick", "Ali"};
        int n1 = array1.length;
        int n2 = array2.length;
        String []array3 = new String[n1 n2];

        for(int i = 0; i < n1; i  )
            array3[i] = array1[i];

        for(int i = n1; i<n2; i  ) {
            int j = 0;
            array3[i] = array2[j  ];
        }

        for(int i = 0; i<array3.length; i  )
            System.out.print(array3[i]   " ");
    }
}

the output should be

Ahmad Adam Mick Ali

but this is what I get

Ahmad Adam null null

CodePudding user response：

Your Second loop's i value is n1 size(2).and loop will continue before n2 size(2).that's why value not added.

Solution: U need add value after 1st array. If you will Store value from 1st array size ,then it will store value perfectly.

public class Q4 {
    public static void main(String[] args){
        String array1[] = new String[]{"Ahmad", "Adam"};
        String array2[] = new String[]{"Mick", "Ali"};
        int n1 = array1.length;
        int n2 = array2.length;
        String []array3 = new String[n1 n2];

        for(int i = 0; i < n1; i  ){
            array3[i] = array1[i];
        }

        for(int i = 0; i<n2; i  ) {
            array3[n1  ] = array2[i];
        }

        for(int i = 0; i<array3.length; i  )
            System.out.print(array3[i]   " ");
    }
}

CodePudding user response：

for(int i = n1; i<n2; i  ) {

the condition inside the second for loop is wrong. As it is now you are starting from size of first array (2) to size of second array (2)

what you want should be

for(int i = n1; i<n2 n1; i  ) {

also you are declaring int j inside the for loop which means j is reset each loop, move its definition outside of the loop or better yet replace it with

i-n1

CodePudding user response：

In the second for loop I should've used i<array3.length instead of i<n2 since i=n1 and n2=n1 so for loop wasn't even excuted