how to make my loop fixed depending on the array elements| C++

Question

I have an array and a for loop. I want the for loop to stop depending on the number of elements the array has.

For example if I have an int array []={1,0,1,0,1} I want the loop to execute code 5 times. Similar to the function for strings .length() but for integers. An example with a simple code would be the best answer :)

like this pseudocode:

for(int b=0;b<array-length;b++)

`sizeof(array)/sizeof(*array)` will evaluate to the number of elements in the array. — George, Dec 05 '16 at 11:01
^^ Provided it's not decayed to a pointer of course. `std::array` or a range based for loop as in the answers are probably your best bet. — George, Dec 05 '16 at 11:11

score 1 · Answer 1 · answered Dec 05 '16 at 11:06

1

Unless you need the index, the following works fine:

int ar[] = { 1, 2, 3, 4, 5 };
for (auto i : ar) {
    std::cout << i << std::endl;
}

answered Dec 05 '16 at 11:06

Nim

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score 1 · Answer 2 · answered Dec 05 '16 at 11:07

1

Since the question is tagged with C++, I'll have to suggest std::vector as the best solution. (Also for the future)

Look into this: std::vector

So for you this'd be like the following:

std::vector<int> array {1,0,1,0,1};
for(int i = 0; i < array.size(); i++)
   ...

Or in the worst case an std::array if you don't want the features of a vector.

See also: std::array

answered Dec 05 '16 at 11:07

SenselessCoder

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I thought of it as I wrote this, added it just now as you put it! – SenselessCoder Dec 05 '16 at 11:08
that sounds like good, do I need to include any libraries? because I get error – Dec 05 '16 at 11:12
Yes you need for vector and for array. – SenselessCoder Dec 05 '16 at 13:04

score 0 · Answer 3 · answered Dec 05 '16 at 11:05

To find length of an array, use this code

int array[5];
std::cout << "Length of array = " << (sizeof(array)/sizeof(*array)) << std::endl;

So in your case, it will be for example:

int array[5];
for(int b=0; b < sizeof(array)/sizeof(*array); b++){
   std::cout << array[b] << std::endl;
}

how to make my loop fixed depending on the array elements| C++

3 Answers3