28 lines
623 B
TypeScript
28 lines
623 B
TypeScript
|
declare global {
|
||
|
|
interface Array<T> {
|
||
|
|
at(index: number): T | undefined;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
if (!Array.prototype.at) {
|
||
|
|
Array.prototype.at = function (index: number) {
|
||
|
|
// Get the length of the array
|
||
|
|
const length = this.length;
|
||
|
|
|
||
|
|
// Convert negative index to a positive index
|
||
|
|
if (index < 0) {
|
||
|
|
index = length + index;
|
||
|
|
}
|
||
|
|
|
||
|
|
// Return undefined if the index is out of range
|
||
|
|
if (index < 0 || index >= length) {
|
||
|
|
return undefined;
|
||
|
|
}
|
||
|
|
|
||
|
|
// Use Array.prototype.slice method to get value at the specified index
|
||
|
|
return Array.prototype.slice.call(this, index, index + 1)[0];
|
||
|
|
};
|
||
|
|
}
|
||
|
|
|
||
|
|
export {};
|