JSFiddle - React, Tailwind, and code Playground

JavaScript

var elem = $('<input type="checkbox" name="checkbox1" value="12345">').prop('checked',true);
console.log(elem.prop("checked"));
console.log(elem[0]);


var elem2 = $('<input type="checkbox" name="checkbox1" value="54321">').attr("checked","checked");
console.log(elem2.prop("checked"));
console.log(elem2[0]);