// *** before: ***
var items = [
    { type: "fruit", name: "apple" },
    { type: "veg", name: "carrot" },
    { type: "fruit", name: "banana" }
];
var grouped = {};
items.forEach(function (item) {
    if (!grouped[item.type]) { grouped[item.type] = []; }
    grouped[item.type].push(item);
});

// *** in version ES2024: ***
const items = [
    { type: "fruit", name: "apple" },
    { type: "veg", name: "carrot" },
    { type: "fruit", name: "banana" }
];
const grouped = Object.groupBy(items, item => item.type);