angular7 深拷貝方法

法一：使用lodash

npm i --save lodash
const _ = require('lodash');
console.log(_.cloneDeep(list));

法二：手動寫個共通方法

public static clone(target: any): any {
    if (target == null) {
        return null;
    }
    const cloneObject = new target.constructor();
    Object.keys(target).forEach(
        (attr: string) => {
            cloneObject[attr] = (typeof target[attr] === 'object') ? this.clone(target[attr]) : target[attr];
        }
    );

    return cloneObject;
}