JS知识点计划

发布时间 2023-12-18 16:07:57作者: 张Blog
tags: JavaScript 前端
author: zhanglei
data: 2023-12-07

Object.assin 不支持低版本浏览器

IE适配

IE11非兼容模式下, 比较新的ES6语法不能使用, Object.assin就是其中之一, 可通过一下方法适配

const target = { a: 1, b: 2 };
const source = { b: 4, c: 5 };
if (typeof Object.assign !== 'function') {
  // Must be writable: true, enumerable: false, configurable: true
  Object.defineProperty(Object, "assign", {
    value: function assign(target, varArgs) { // .length of function is 2
      'use strict';
      if (target === null || target === undefined) {
        throw new TypeError('Cannot convert undefined or null to object');
      }

      var to = Object(target);

      for (var index = 1; index < arguments.length; index++) {
        var nextSource = arguments[index];

        if (nextSource !== null && nextSource !== undefined) { 
          for (var nextKey in nextSource) {
            // Avoid bugs when hasOwnProperty is shadowed
            if (Object.prototype.hasOwnProperty.call(nextSource, nextKey)) {
              to[nextKey] = nextSource[nextKey];
            }
          }
        }
      }
      return to;
    },
    writable: true,
    configurable: true
  });
}
const returnedTarget = Object.assign(target, source);

console.log(target);