数组去重

写一个方法将下面 arr 中的数据去重，去重后的结果应为result所示结果

const arr = [
    'null',
     null,
     null,
     undefined,
     {},
     {name: 'xiaoyu'},
     {name: 'xiaoyu'},
     {title: 'xiaoyu'},
     {name: undefined},
     {}
];
const result = ['null', null, undefined, {}, {name: 'xiaoyu'}, {title: 'xiaoyu'}, {name: undefined}];

// 题解：
/*工具函数*/
function isEqual(o1, o2) {
    if ((typeof o1 === 'object' && o1 !== null) && (typeof o2 === 'object' && o2 !== null)) {
        let keys1 = Object.keys(o1);
        let keys2 = Object.keys(o2);

        if (keys1.length === 0 && keys2.length === 0) {
            return true;
        }
        if (keys1.length !== keys2.length) {
            return false;
        }
        for (let key of keys1) {
            if (!o2.hasOwnProperty(key) || o2[key] !== o1[key]) {
                return false
            }
        }
        return true;
    }
    return o1 === o2;
}

/*主函数*/
function main(sourceArr) {
    let result = [];
    for (let i = 0; i < sourceArr.length; i++) {
        if (typeof sourceArr[i] === 'object' && sourceArr[i] !== null) {
            if (!result.find(item => isEqual(item, sourceArr[i]))) {
                result.push(sourceArr[i])
            }
        } else {
            !result.includes(sourceArr[i]) && result.push(sourceArr[i])
        }
    }
    return result;
}