The code below run but didn't works as i want..why ?

Question

https://code.sololearn.com/cFyT4Pyiun30/?ref=app

Answer 1

Yea if you want b to be the loop count.

Something like this:

for(; b >= 0; b--){

}

PS: The cout line shouldn't have those commas. Look at how @Enas separated the lines with <<.

Answer 2

//Is that what you want ?

#include <iostream>
using namespace std;

int main()
{
cout<<"how many of phone numbers you wanna save ?";
int b;

cin>>b;

long int num [b];
for (int i=0;i<b;i++) {
cout<<"phone number"<<b<<"\n";

cin>>num[b];
cout<<num[b];
}

return 0;
}

Answer 3

I'm actually surprised that it runs at all. Usually a compiler would be upset that you are trying to use a runtime variable to initialize an array:

long int num [b];

You have to use a vector or an array from the array header or a pointer.

vector<long int> num(b);

long int* num = new long int[b];
delete [] num;

Then, you need a separate variable for your loop. There's no other way around that. Just do this:

for (int i = 0; i < b; i++) {
// do stuff
}

Answer 4

Have a look at your for loop.
for(b = 0; b; b++)

The condition is b??
so.. the condition is false I guess. Since 0 is false.

So, There's nothing to run in the loop.

Answer 5

yes i tried that before..but i don't want to add another variable like "i" as you did..i want just to work with the first variable "b"..isn't it possible ?

Answer 6

it works..thank u :) that what i want

Answer 7

Here is the version I made that works.

https://code.sololearn.com/c8u45vocT5zX

Answer 8

yes i got it...thank u so much for this version..actually i don't know yet about vector, but i'll will learn it