Script to compare performance of Object values iterating techniques | Performance Comparison [https://gists.cwidanage.com/2018/06/how-to-iterate-over-object-entries-in.html]

object_it_performance.js

const { PerformanceObserver, performance } = require('perf_hooks');

let objectSize = 1000000;
let iterations = 100;

console.log("Starting performance test with %d object size and %d iterations",
    objectSize, iterations);

let values = {
    ENTRIES: 0,
    ENTRIES_FOR: 0,
    KEYS: 0,
    KEYS_FOR: 0,
    VALUES: 0,
    VALUES_FOR: 0,
    FORIN: 0,
    GETOWP: 0,
    GETOWP_FOR: 0
}

const obs = new PerformanceObserver((items) => {
    let entry = items.getEntries()[0];
    console.log(entry.name, entry.duration);
    values[entry.name] += entry.duration;
    performance.clearMarks();
});
obs.observe({ entryTypes: ['measure'] });

function generateObject() {
    let obj = {};
    for (let i = 0; i < objectSize; i++) {
        obj['key' + i] = 'val' + i;
    }
    return obj;
}

for (let i = 0; i < iterations; i++) {
    let obj = generateObject();

    //Object.entries
    performance.mark('A');
    Object.entries(obj).forEach(entry => {
        let key = entry[0];
        let value = entry[1];
    });
    performance.mark('B');
    performance.measure('ENTRIES', 'A', 'B');

    //Object.entries with for
    performance.mark('A');
    let entries = Object.entries(obj);
    for (let i = 0; i < entries.length; i++) {
        let key = entries[i][0];
        let value = entries[i][1];
    }
    performance.mark('B');
    performance.measure('ENTRIES_FOR', 'A', 'B');


    //Object.Keys
    performance.mark('A');
    Object.keys(obj).forEach(key => {
        let value = obj[key];
    });
    performance.mark('B');
    performance.measure('KEYS', 'A', 'B');

    //Object.Keys with for
    performance.mark('A');
    let keys = Object.keys(obj);
    for (let i = 0; i < keys.length; i++) {
        let value = obj[keys[i]];
    }
    performance.mark('B');
    performance.measure('KEYS_FOR', 'A', 'B');

    //Object.Values
    performance.mark('A');
    Object.values(obj).forEach(value => {

    });
    performance.mark('B');
    performance.measure('VALUES', 'A', 'B');

    //Object.Values with for
    performance.mark('A');
    let values = Object.values(obj);
    for (let i = 0; i < values.length; i++) {
        let value = values[i];
    }
    performance.mark('B');
    performance.measure('VALUES_FOR', 'A', 'B');

    //For In
    performance.mark('A');
    for (const key in obj) {
        if (obj.hasOwnProperty(key)) {
            let value = obj[key];
        }
    }
    performance.mark('B');
    performance.measure('FORIN', 'A', 'B');

    //Object.getOwnPropertyNames
    performance.mark('A', i);
    Object.getOwnPropertyNames(obj).forEach(key => {
        let value = obj[key];
    });
    performance.mark('B');
    performance.measure('GETOWP', 'A', 'B');

    //Object.getOwnPropertyNames with for
    performance.mark('A');
    let props = Object.getOwnPropertyNames(obj);
    for (let i = 0; i < props.length; i++) {
        let value = obj[props[i]];
    }
    performance.mark('B');
    performance.measure('GETOWP_FOR', 'A', 'B');
}


console.log(Object.entries(values).sort((a, b) => {
    return a[1] - b[1];
}).map(obj => {
    obj[1] /= iterations;
    return obj;
}));