js 数组去重

封装了几个js对数组的处理

1.获取数组中某一列的全部内容

let arr = [
  {
   id:'232122',
   name: '张三'
  },{
    id:'12122',
    name:'王二',

function array_column(arr, column) {
  return arr.map(x => x[column])
}

array_column(arr,'name');

// ['张三','王二']

2.数组去重

let arr = [1,1,1,2,3];
 function array_unique(arr) {
  return [...new Set(arr)];
}
array_unique(arr);

//[1,2,3]

3.二维数组去重

let matrix=[
        [1,2,3,4],
        [3,4,5,6],
        [1,2,3,4]
    ]

function array_unique_two_dimensional(arr) {
 var obj = {};
    for (var i = 0; i < arr.length; i++) {
      // 判断当前项是否遍历过，是则删除，否存入obj以作对照
      if (obj.hasOwnProperty(arr[i])) {
        arr.splice(i, 1)
        i++;
      }
      obj[arr[i]] = i;
    }
    return arr;
   };

array_unique_two_dimensional(matrix);

// [[3,4,5,6],
        [1,2,3,4]];

4.二维数组去重，指定字段

let arr = [
  {
   id:'232122',
   name: '张三'
  },{
    id:'12122',
    name:'王二',
  },
  {
    id:'121322',
    name:'王二',
  }
];

function array_unique_two_dimensional(arr,param = ''){
    const res = new Map();
    return arr.filter((a) => !res.has(a[param]) && res.set(a[param], 1))
}

array_unique_two_dimensional(arr,'name');

//[{
   id:'232122',
   name: '张三'
  },{
    id:'12122',
    name:'王二',
  }]