JS-Interpreter Sort Demo

JavaScript's Array.sort function takes an optional argument that is used by sort as a comparator function. This is difficult to replicate in the JS-Interpreter, since execution would need to step through this function an arbitrary number of times. As a result, the provided Array.sort function does not support custom comparator functions.

If this functionality is needed, the easiest way to implement it is to monkey patch the environment at runtime. Just add the Array.prototype.sort definition shown below, and custom comparator functions will be fully supported.

Click Parse, then either click Step repeatedly, or click Run once. Open your browser's console for errors.

Array.prototype.sort = function(opt_comp) { for (var i = 0; i < this.length; i++) { var changes = 0; for (var j = 0; j < this.length - i - 1; j++) { if (opt_comp ? opt_comp(this[j], this[j + 1]) > 0 : this[j] > this[j + 1]) { var swap = this[j]; this[j] = this[j + 1]; this[j + 1] = swap; changes++; } } if (changes > 1) break; } return this; }; alert(['C', 'a', 'd', 'B'].sort(function (a, b) { return a.toLowerCase().localeCompare(b.toLowerCase()); }));
Parse Step Run

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