Untitled

let string = "";

let buttons = document.querySelectorAll('.button');

buttons.forEach((button) => {
    button.addEventListener('click', (e)=> {
        if(e.target.innerHTML == '='){
            string = eval(string);
            document.querySelector('input').value = string;
        }else if(e.target.innerHTML == 'c'){
            string = "";
            document.querySelector('input').value = string;
        }else{
            string = string + e.target.innerHTML;
            document.querySelector('input').value = string;
        }
    }); 
});