JSFiddle - React, Tailwind, and code Playground
HTML
<div id="mains">click here to get first four then</div>
<button id="fourmore">GET 4 MORE</button>
<div id="pm-page-main"></div>
JavaScript
$(document).ready(function() {
var a;
var b;
var y;
var z;
var pmmain = ["aaa", "bbb", "ccc", "ddd", "eee", "fff", "ggg", "hhh", "iii", "jjj", "kkk", "lll", "mmm", "nnn", "ooo", "ppp"];
$("#mains").one("click", function() {
y = 0;
z = y +4;
a = 4;
b = 0;
for ( a=y; a < z; a++) {
$("#pm-page-main").append("<div class=\"main-box\"><div class=\"title-box\"><span class=\"reg-wht-bold\">" + pmmain[a] + "</span></div><BR><BR><img src=\"imgs\\" + pmmain[a] + ".png\"></div>");
}
});
$("#fourmore").click(function() {
b= a
z = b +4;
for (b=a; b < z; b++) {
$("#pm-page-main").append("<div class=\"main-box\"><div class=\"title-box\"><span class=\"reg-wht-bold\">" + pmmain[b] + "</span></div><BR><BR><img src=\"imgs\\" + pmmain[b] + ".png\"></div>");
}
a = a+4;
});
});