CODEWITHSUNDEEP
javaarrays
Higuy333
Higuy333

Reputation: 3

How to change variable of element in a loop?

Im not exactly sure how to word this, I am trying to access different variables within a loop. Here is an example:

int[] box0 = {1,2,3};
int[] box1 = {4,5,6};


for(int i = 0; i < 2; i++){
    
    box'i'[i] = 0;  //Where I first change the elements of the box0 array then of box1 array.
}

I do not know how to concatenate, access, or otherwise use the other array. I am pretty new to java so please keep solutions as simple as possible. Thanks.

Upvotes: 0

Views: 141

Answers (2)

Nowhere Man
Nowhere Man

Reputation: 19545

It would make sense to use array of arrays and then address an element of such array:

int[] box0 = {1, 2, 3};
int[] box1 = {4, 5, 6};
int[][] box = {box0, box1};

for (int i = 0; i < 2; i++) {
    box[i][i] = 0; // however, here an elements are changed at diagonal cells
}

If all elements need to be changed by "row", a nested loop should be used:

int[] box0 = {1, 2, 3};
int[] box1 = {4, 5, 6};
int[][] box = {box0, box1};

for (int i = 0; i < box.length; i++) {
    for (int j = 0; j < box[i].length; j++) {
        box[i][j] = 0;
    }
}

Upvotes: 1

KingKevin23
KingKevin23

Reputation: 111

It really depends on what you're trying to do. I cannot really determine what you are trying to achieve so I'm giving multiple possible options:

Iterate through an array

int[] box0 = {1,2,3};
int[] box1 = {4,5,6};


for(int i = 0; i < 3; i++)
{
    box0[i] = 0;
}

This code will iterate over the elements 0 to 3 of the box0 array and set the value to 0.

Result:

box0 = [0, 0, 0]
box1 = [4, 5, 6]

Iterate over multiple arrays

int[] box0 = {1,2,3};
int[] box1 = {4,5,6};
int[][] allArrays = {box0, box1};

for(int i = 0; i < 2; i++)
{
    allArrays[i][0] = 5;
}

This code will iterate over the elements 0 to 2 of the allArrays array (which contains both arrays box0 and box1) and set the value of their first element to 5.

Result:

box0 = [5, 2, 3]
box1 = [5, 5, 6]
allArrays = [[5, 2, 3], [5, 5, 6]]

Upvotes: 1

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