Question

为什么点差运算符会将“Stratford”的值替换为“HB woodlawn”？这是如何工作的？

const editName = (oldName, name, arr) =>
  arr.map(item => {
    if (item.name === oldName) {
      return {
        ...item,
        name
      }
    } else {
      return item
    }
  })

let schools = [
  { name: "Yorktown"},
  { name: "Stratford" },
  { name: "Washington & Lee"},
  { name: "Wakefield"}
]
let updatedSchools = editName("Stratford", "HB Woodlawn", schools)
console.log( updatedSchools[1] ) // { name: "HB Woodlawn" }
console.log( schools[1] ) // { name: "Stratford" },

Answer 1

归结为：

const oldObject = { name: 'Stratford' };
const newObject = { ...oldObject, name: 'HB Woodlawn' };

您可以将其视为将oldObject的属性扩展为新的对象文字：

const newObject = { name: 'Stratford', name: 'HB Woodlawn' };

文字中具有相同键的属性获取最后一个的值。

传播运营商取代价值？

1 个答案: