CODEWITHSUNDEEP
c++objective-carraysnsstringcopying
jundl77
jundl77

Reputation: 476

Putting String into a 2D Matrix in Objective C++

So I'm using Objective C++ and I want to put a string into a 4 by X (X = length of string/4) int array by using the ASCII code. The first quarter of the string (which is formatted to fit completely into a 4 by X array) is supposed to go in [0][col], the second quarter into [1][col], the third quarter into [2][col] and the fourth quarter into [3][col]. So I tried the following with 4 for loops, but it doesnt work at all, and I just can't seem to get it to work somehow. Any suggestions would be greatly appreciated.

textMatrix is the matrix in which I want to put the NSString/ASCII number, and inputFinal is the NSString itself. Length * (1/4) or whatever is also always going to be an integer.

for(int i = 0; i < length*(1/4); i++)
{
    textMatrix[0][i] = (int)[inputFinal characterAtIndex: i];
}
for(int j = length*(1/4); j < length*(2/4); j++)
{
    textMatrix[1][j] = (int)[inputFinal characterAtIndex: j];

}
for(int k = length*(2/4); k < length*(3/4); k++)
{
    textMatrix[2][k] = (int)[inputFinal characterAtIndex: k];
}
for(int l = length*(3/4); l < length; l++)
{
    textMatrix[3][l] = (int)[inputFinal characterAtIndex: l];
}

Upvotes: 0

Views: 599

Answers (3)

jundl77
jundl77

Reputation: 476

actually a double loop like so ended up working best for me: 

int index = 0;
for(int row = 0; row < 4; row++)
{
    for(int col = 0; col < length/4; col++)
    {
        textMatrix[row][col] = (int)[inputFinal characterAtIndex:index];
        index++;
    }
}

Upvotes: 0

bsarr007
bsarr007

Reputation: 1964

You can rewrite your 4 loops in 1 loop:

 for(int i = 0; i < length; i++)
 {
   textMatrix[i/4][i%4] = (int)[inputFinal characterAtIndex:i];
 }

Upvotes: 1

Brandon
Brandon

Reputation: 23498

I don't think I understand what you're trying to do..

Given a string: "Here";

do you want:

Matrix[0][0] = 'H';
Matrix[1][1] = 'e';
Matrix[2][2] = 'r';
Matrix[3][3] = 'e';

If so then this works:

#import <objc/objc.h>
#import <objc/Object.h>
#import <Foundation/Foundation.h>

@implementation TestObj
int main()
{
    NSString* str = @"Here";

    int matrix[4][4] = {0};

    for (int i = 0, j = 0; j < 4; ++j)
    {
        matrix[i][i++] = (int) [str characterAtIndex: j];
    }

    for (int i = 0; i < 4; ++i)
    {
        for (int j = 0; j < 4; ++j)
        {
            printf("%c", (char)matrix[i][j]);
        }
    }

    return 0;
}
@end

The above prints Here.

Upvotes: 0

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