Why does cin, expecting an int, change the corresponding int variable to zero in case of invalid input ?

Question

Moreover , when I give input a and Enter it takes 0 for first integer and -1098876708
code :
int a,b;
cout<<"enter "<<endl;
cin>>a>>b;
cout<<a<<" "<<b;

Answer 1

What is your input?

Answer 2

If input "a" is 5 and input "b" is hello the output will be 5 0. Remember that in SoloLearn you must enter multiple inputs on separate lines.

#include<iostream>
using namespace std;
int main () {
int a, b;
cout << "Enter (a) and (b) " << endl;
// If user inputs
// 5 && hello
cin >> a >> b;
// The output will be
// 5 0
cout << a << " " << b << endl;
return 0;
}