Is there a way to declare a Object with the same key names in js ?
let Obj = {
'1' : '1',
'1' : '1',
'1' : '1',
}
No. The names of the properties in an object must be unique, not least so you can identify the property you want to get/set. Although the code you wrote will parse and run, the resulting object will have only one property (the last one using that name):
let obj = {
1: "first",
1: "second",
1: "third",
};
console.log(obj[1]);; // "third"You could use an array of objects if the key name must be the same:
let array = [
{1: 1},
{1: 1},
{1: 1},
];
...or, really, just an array (let array = [1, 1, 1];) as the key name isn't doing anything useful if it's always the same.