js处理数组某个字段去重的方法

1. 使用Set数据结构

const arr = [{id: 1, name: 'apple'}, {id: 2, name: 'banana'}, {id: 3, name: 'apple'}, {id: 4, name: 'orange'}];
const uniqueNames = [...new Set(arr.map(item => item.name))];
console.log(uniqueNames); // ['apple', 'banana', 'orange']

2. 使用reduce方法

const arr = [{id: 1, name: 'apple'}, {id: 2, name: 'banana'}, {id: 3, name: 'apple'}, {id: 4, name: 'orange'}];
const uniqueNames = arr.reduce((acc, cur) => {
  if (!acc.includes(cur.name)) {
    acc.push(cur.name);
  }
  return acc;
}, []);
console.log(uniqueNames); // ['apple', 'banana', 'orange']

3. 使用filter方法

const arr = [{id: 1, name: 'apple'}, {id: 2, name: 'banana'}, {id: 3, name: 'apple'}, {id: 4, name: 'orange'}];
const uniqueNames = arr.filter((item, index, array) => {
  return array.findIndex(i => i.name === item.name) === index;
}).map(item => item.name);
console.log(uniqueNames); // ['apple', 'banana', 'orange']

4. 使用forEach方法

const arr = [{id: 1, name: 'apple'}, {id: 2, name: 'banana'}, {id: 3, name: 'apple'}, {id: 4, name: 'orange'}];
const uniqueNames = [];
arr.forEach(item => {
  if (!uniqueNames.includes(item.name)) {
    uniqueNames.push(item.name);
  }
});
console.log(uniqueNames); // ['apple', 'banana', 'orange']