checkbox选中后新增内容数组（typescript）

/**
 * Created by Administrator on 2018/4/16.
 */
export class CheckBoxUtil {

    /**
     * 单选
     * @param e $event 事件
     * @param item 选中对象
     * @param selectedItem 更新后的数组
     */
    public static updateSelected(e: any, item: any, selectedItem: any[]) {
        const obj = e.target;
        let addFlag = true;
        if (selectedItem.length > 0) {
            selectedItem.forEach(data => {
                if (CheckBoxUtil.diff(data, item)) {
                    addFlag = false;
                }
            });
        }
        if (typeof (obj.checked) == "undefined") {
            if (obj && addFlag) {
                console.log('执行添加');
                selectedItem.push(item);
            }
            if (obj && !addFlag) {
                console.log('执行删除');
                selectedItem.splice(selectedItem.indexOf(item), 1);
            }
        } else {
            if (obj.checked && addFlag) {
                console.log('checkbox执行添加');
                selectedItem.push(item);
            }
            if (!obj.checked && !addFlag) {
                console.log('checkbox执行删除');
                selectedItem.splice(selectedItem.indexOf(item), 1);
            }
        }
    }

    /**
     * 判断俩对象是否为同一对象
     * @param obj1
     * @param obj2
     * @returns {boolean}
     */
    private static diff(obj1: any, obj2: any): boolean {
        let o1 = obj1 instanceof Object;
        let o2 = obj2 instanceof Object;
        if (!o1 || !o2) {/*  判断不是对象  */
            return obj1 === obj2;
        }

        if (Object.keys(obj1).length !== Object.keys(obj2).length) {
            return false;
            //Object.keys() 返回一个由对象的自身可枚举属性(key值)组成的数组,例如：数组返回下表：let arr = ["a", "b", "c"];console.log(Object.keys(arr))->0,1,2;
        }

        for (let attr in obj1) {
            let t1 = obj1[attr] instanceof Object;
            let t2 = obj2[attr] instanceof Object;
            if (t1 && t2) {
                return this.diff(obj1[attr], obj2[attr]);
            } else if (obj1[attr] !== obj2[attr]) {
                return false;
            }
        }
        return true;
    }
}