I hope you have read this page: http://terminalcoders.blogspot.com/2014/07/searching.html. If you didn't read it, please read it before using the source code.
#include <iostream> using namespace std; class OLS { int list[256], n, i, k; public: void read() { cout<<"Enter the number of items: "; cin>>n; cout<<"Enter "<<n<<" Items in ascending order: "; for(i=0;i<n;i++) { cin>>list[i]; } cout<<"Enter key to search: "; cin>>k; o_l_s(); } void o_l_s() { i=0; while(i<n && k>list[i]) { i++; } if(list[i]==k) { cout<<"Key has found!!!"; } else { cout<<"Key hasn't found!!!"; } } }; int main() { OLS o; o.read(); }