The JavaScript Array object extends the indexOf of method
- 2020-03-30 02:52:25
- OfStack
Background: the standard method for Array objects in JavaScript does not include an indexOf() method, which can be extended with the following code.
if (!Array.prototype.indexOf) {
Array.prototype.indexOf = function(elt) {
var len = this.length >>> 0;
var from = Number(arguments[1]) || 0;
from = (from < 0) ? Math.ceil(from) : Math.floor(from);
if (from < 0) from += len;
for (; from < len; from++) {
if (from in this && this[from] === elt) return from;
}
return - 1;
};
}