megamorphic-has-prop.js

Enable keyboard shortcuts

function hasOwnProp(o, p) {

    return Object.prototype.hasOwnProperty.call(o, p);

function testHasProp() {

    var C = Object.create(null);

    C.protox = 0;

    var B = Object.create(C);

    var objs = [];

    for (var i = 0; i < 50; i++) {

        var A = Object.create(B);

        A["x" + i] = 0;

        A.ownx = 3;

        objs.push(A);

    for (var i = 0; i < 10; i++) {

        for (var j = 0; j < objs.length; j++) {

            var obj = objs[j];

            assertEq(hasOwnProp(obj, "protox"), false);

            assertEq("protox" in obj, true);

            assertEq(obj.protox, 0);

            assertEq(hasOwnProp(obj, "ownx"), true);

            assertEq("ownx" in obj, true);

            assertEq(obj.ownx, 3);

            assertEq("missing" in obj, false);

            assertEq(hasOwnProp(obj, "missing"), false);

            assertEq(obj.missing, undefined);

testHasProp();