sequental search cin is not working

[miloserdniy5]

Write your question here.
why it's not working correct. cin is not working

#include <iostream>

using namespace std;

const int LEN = 10;

int arr[LEN] = {4, 40, 20, 17, 25, 445, 78, 23, 91, 20};


int main(){

    int key;

    cout << "Enter key please: ";
    //cout << arr[1];
    cin >> key;// = 40;
    
    int i = 0;

    while(i < LEN){

        if (arr[i]==key ){
           cout << "We got key into array arr.\n";
        }

    }

}

[lastchance]

Where are you planning to change i? Or are you going to leave it with the value 0, so always indexing the beginning of the array.

[dhayden]

You never change i inside the loop, so it loops forever with i==0. To fix it, add i++; at line 25. Better yet, use a for loop:

    for (int i = 0; i < LEN; ++i) {
        if (arr[i]==key ){
           cout << "We got key into array arr.\n";
        }
    }

Or best of all, use a range-based for loop:

for (int val : arr) {
    if (val == key) {
           cout << "We got key into array arr.\n";
   }
}

Note that all of these solutions will keep looking for a match, even after they find one. To stop looking after finding the first match, add break; right after the cout statement.