I'm doing an exercise where I have to print the original array and add more elements to the array and print those too. So the output should be
Original array:
[10, 20, 30]
After append values to the end of the array:
[10 20 30 40 50 60 70 80 90]
The second part is printing but for some reason, the original array elements won't print.
int arr[9] = {10, 20, 30};
cout << "The original array elements are : " << endl;
for (int i = 0; arr[i] <= 3; ++i)
{
cout << arr[i] << endl;
}
arr[3] = {40};
arr[4] = {50};
arr[5] = {60};
arr[6] = {70};
arr[7] = {80};
arr[8] = {90};
cout << "After append values to the end of the array : " << endl;
for (int j = 0; arr[j] >= 9; ++j)
{
cout << arr[j] << endl;
}
This is the code that I've written, could someone please tell me what I'm doing wrong?
Because
for (int i = 0; arr[i] <= 3; ++i)
Means "loop until arr[i]<=3
", which is always false in your case.
You probably want instead this:
for (int i = 0; i < 3; ++i)
Same thing with the second loop, instead of arr[j] >=9
you probably want j < 9
After this changes the output is this:
The original array elements are :
10
20
30
After append values to the end of the array :
10
20
30
40
50
60
70
80
90
for (int i = 0; arr[i] <= 3; ++i)
Should be
for (int i = 0; i < 3; ++i)
and similarly the j
-loop should check for j < 9
, because you want to check the number of elements (3 and 9) printed, not their values.
If you want to use a for loop to print elements of an array, you have two options. You can use a traditional for loop with a loop counter like i
. This is usually preferred if you want to iterate over a partial range. You usually compare the loop counter with the last index. On the other hand, if you are going to iterate over the whole thing, a more convenient option is to use a range-based for loop. You can see both examples here:
#include <iostream>
int main() {
int arr[9] = {10, 20, 30};
std::cout << "The original array elements are :\n";
// Traditional for-loop
for (int i = 0; i <= 3; ++i) {
std::cout << arr[i] << '\n';
}
arr[3] = {40};
arr[4] = {50};
arr[5] = {60};
arr[6] = {70};
arr[7] = {80};
arr[8] = {90};
std::cout << "After append values to the end of the array :\n";
// Range-based for loop
for (auto const elm : arr) {
std::cout << elm << '\n';
}
}
Learn more about for loops here .
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