If there is a prev button next button, can I change the URL by making it i-- when I press the prev button, and i++ when I press the next button?

var prevBtn = document.getElementById("prev");
var nextBtn = document.getElementById("next");
var i = 0;
var getPathname = window.location.pathname;
var repetitivePath = getPathname.substring(0, getPathname.lastIndexOf("/") + 1);

function minus(){
    i--;
    if ( i === -1){
        i = 0;
    }
    // // var repetitivePath = getPathname.substring(0, getPathname.lastIndexOf("/") + 1);
    // // window.location.href = repetitivePath + i + ".html";
    window.location.replace(repetitivePath + i + '.html');
    console.log(i);
    // // console.log(repetitivePath);
}

function plus(){
    i++;
    if ( i === 3){
        i = 2;
    }
    // // var repetitivePath = getPathname.substring(0, getPathname.lastIndexOf("/") + 1);
    // // window.location.href = repetitivePath + i + ".html";
    window.location.replace(repetitivePath + i + '.html');
    console.log(i);
    // // console.log(repetitivePath);
}


prevBtn.addEventListener("click", function(){
    minus();
})

nextBtn.addEventListener("click", function(){
    plus()
})