qt-everywhere-src-5.15.1/qtdeclarative/tests/manual/v4/sparsearraytest.js

var max
for (max = 2; max < 100; ++max) {
    var arr = [];
    // force a sparse array
    Object.defineProperty(arr, "0", {
        get: function () {
            return 0;
        },
        configurable: true
    });
    var i;
    var j;
    for (i = 1; i < max; ++i)
        arr[i] = i;
    for (i = 1; i < max; i += 2) {
        delete arr[i];
        for (j = 0; j < max; ++j) {
            if (j <= i && (j %2)) {
                if (arr[j] != undefined)
                    throw "err1"
            } else {
                if (arr[j] != j)
                    throw "err2"
            }
        }
    }
}

for (max = 2; max < 100; ++max) {
    var arr = [];
    // force a sparse array
    Object.defineProperty(arr, "0", {
        get: function () {
            return 0;
        },
        configurable: true
    });

    var i;
    var j;
    for (i = 1; i < max; ++i)
        arr[i] = i;
    for (i = 0; i < max; i += 2) {
        delete arr[i];
        for (j = 0; j < max; ++j) {
            if (j <= i && !(j %2)) {
                if (arr[j] != undefined)
                    throw "err1 " + i + " " + j + " " + arr[j]
            } else {
                if (arr[j] != j)
                    throw "err2 " + j
            }
        }
    }
}