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ES6 getter & setter

ES6 getter & setter


"use strict";

/**
 *
 * @author xgqfrms
 * @license MIT
 * @copyright xgqfrms
 * @created 2020-09-30
 * @modified
 *
 * @description
 * @difficulty Easy
 * @complexity O(n)
 * @augments
 * @example
 * @link https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/get
 * @link https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/set
 * @link
 * @solutions
 *
 * @best_solutions
 *
 */

const log = console.log;

// 1. class getter & setter
class Test {
  // ❌👎 重名 bug, RangeError: Maximum call stack size exceeded
  // constructor() {
  //   this.age = 0;
  // }
  // set age(num) {
  //   this.age = `${num} year`;
  // }
  // get age() {
  //   return this.age;
  // }
  constructor() {
    // ✅👍 不可以重名,防止 call stack overflow
    this._age = 0;
  }
  set age(num) {
    this._age = `${num} year`;
  }
  get age() {
    log(`\nthis`, this);
    return this._age;
  }
}


const t = new Test();

log(`t.age =`, t.age)

t.age = 18;

log(`t.age =`, t.age)

/*

$ node class.js

this Test { _age: 0 }
t.age = 0

this Test { _age: '18 year' }
t.age = 18 year

*/




"use strict";

/**
 *
 * @author xgqfrms
 * @license MIT
 * @copyright xgqfrms
 * @created 2020-09-30
 * @modified
 *
 * @description
 * @difficulty Easy
 * @complexity O(n)
 * @augments
 * @example
 * @link https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/get
 * @link https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/set
 * @link
 * @solutions
 *
 * @best_solutions
 *
 */

const log = console.log;


// 2. object setter & getter

const obj = {
  arr: ["A", "B", "C"],
  get latest() {
    return this.arr[this.arr.length - 1];
  },
  set latest(value) {
    return this.arr[this.arr.length - 1] = value;
  }
};

log(`\nobj.latest =`, obj.latest);
obj.latest = "XYZ";
log(`\nobj.latest =`, obj.latest);

/*

obj.latest = C

obj.latest = XYZ

*/


https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/get

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/set

refs



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posted @ 2020-10-01 08:31  xgqfrms  阅读(156)  评论(1编辑  收藏  举报