CODEWITHSUNDEEP
c++arrays
CoderRightInTheProgram
CoderRightInTheProgram

Reputation: 127

Range based for loop incorrectly outputs element of array with cout

The following code correctly outputs the elements of an array for the first two for statements, but in the third it incorrectly outputs the elements of the array from a range based for loop when using cout (works with printf in the first). Why is this?

#include <iostream>
using namespace std;

int main( int argc, char ** argv )
{

int myArray[]={10,20,30,40,50};

for (int i : myArray) {
    printf("%d\n", i);
}


for (int i = 0 ; i < 5; i++) {
    cout << myArray[i] << endl;
}

for (int i : myArray) {
    cout << myArray[i] << endl;
}


return 0;
}

the output:

10
20
30
40
50
10
20
30
40
50
-1707465271
0
1606417258
1606417820
1606418039

Upvotes: 0

Views: 82

Answers (3)

Jarod42
Jarod42

Reputation: 217085

You have out of bound access in

for (int i : myArray) {
    cout << myArray[i] << endl;
}

as i would be 10,20,30,40,50.

you want

for (int i : myArray) {
    cout << i << endl;
}

as you do with printf.

Upvotes: 4

Steephen
Steephen

Reputation: 15824

You dont need to use index variable while using range based for loop, instead you need a local variable to retrieve the data from container or array that you need to loop

for (int i : myArray) {
    cout << myArray[i] << endl;
}

The above snippet of code should correct as follows:

for (int i : myArray) {
    cout << i << endl;
}

Upvotes: 0

Vlad from Moscow
Vlad from Moscow

Reputation: 310930

Change it the following way

for (int i : myArray) {
    cout << i << endl;
}

It is the same loop as you wrote before it with using printf

for (int i : myArray) {
    printf("%d\n", i);
}

Take into account that you should include header <cstdio>

Upvotes: 1

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