如何获取数组中的公共值

Question

例如，我有一个数据数组如下

var arrData = ["40-25",null,null,"40-25","50-48",null,"30-25","40-23","50-48","30-25",null,"50-48","40-45","40-45","40-45","40-50","40-50",null,null,null,null,null,"50-48"]

我需要在javascript中列出与下面相同的数据

var arrDataSorted = ["40-25","50-48","30-25","40-23","40-45","40-50","40-50"]

只需要复制空值的公共数据被删除。

解决此问题的最佳解决方案是什么。

Answer 1

您可以尝试使用Array.prototype.filter()删除空值并使用Set获取唯一值。 最后使用Spread syntax (...)将集合结果转换为数组。

尝试以下方式：

 var arrData = ["40-25",null,null,"40-25","50-48",null,"30-25","40-23","50-48","30-25",null,"50-48","40-45","40-45","40-45","40-50","40-50",null,null,null,null,null,"50-48"]; var arrDataSorted = [...new Set(arrData.filter(i => i))]; console.log(arrDataSorted);

Answer 2

您可以从一个数组创建一个集合，它会自动删除重复项：

let arrData = ["40-25",null,null,"40-25","50-48",null,"30-25","40-23","50-48","30-25",null,"50-48","40-45","40-45","40-45","40-50","40-50",null,null,null,null,null,"50-48"];

let set = new Set(arrData);

这仍然会保留空值，您可以通过delete调用将其delete ，并使用 spread ...运算符将其转换回数组。 最终代码将是：

let set = new Set(arrData);
set.delete(null);
let distinctArr = [...set];

Answer 3

如果值不为null ，则将值添加到集合中并将其转换为数组。

 var arrData = ["40-25",null,null,"40-25","50-48",null,"30-25","40-23","50-48","30-25",null,"50-48","40-45","40-45","40-45","40-50","40-50",null,null,null,null,null,"50-48"]; var setData = new Set(); for(var data of arrData) { if(data) { setData.add(data); } } var arrDataSorted = [...setData]; console.log(arrDataSorted);

Answer 4

将此函数添加到您的代码中：

function removeCommonValues(arr) {
  let result = [];
  for(let i=0; i < arr.length-1; ++i) {
    if(result.includes(arr[i]) === false && arr[i] !== null)
      result.push(arr[i])
  }
  return result
}

用法：

removeCommonValues(["40-25",null,null,"40-25","50-48",null,"30-25","40-23","50-48","30-25",null,"50-48","40-45","40-45","40-45","40-50","40-50",null,null,null,null,null,"50-48"]) // Return ["40-25", "50-48", "30-25", "40-23", "40-45", "40-50"]

Answer 5

var arrData = ["40-25",null,null,"40-25","50-48",null,"30-25","40-23","50-48","30-25",null,"50-48","40-45","40-45","40-45","40-50","40-50",null,null,null,null,null,"50-48"]
var set = new Set();
      for ( var i = 0 ; i< arrData.length;i++ ) {
           if(arrData[i]!==null) {
                set.add(arrData[i]);
           }
      }
var newArr = [...set]

Answer 6

您可以使用数组内置的 reducer 方法，在下一个代码中，我从一个空数组开始，我只返回不为空且不在数组中的项目。

const data = arrData.reduce((state, value) => {
   if(value && !state.includes(value)) {
        return [...state, value];
   }

   return state;
}, [])

Answer 7

该函数可以在一个单独的文件中，以便在多个页面之间重复使用。 然后您可以调用该函数来过滤非空的不同值。

 var arrData = ["40-25",null,null,"40-25","50-48",null,"30-25","40-23","50-48","30-25",null,"50-48","40-45","40-45","40-45","40-50","40-50",null,null,null,null,null,"50-48"]; function fn(value,index,self){ return self.indexOf(value) === index && value; } console.log(arrData.filter(fn));

Answer 8

 var arrData = ["40-25",null,null,"40-25","50-48",null,"30-25","40-23","50-48","30-25",null,"50-48","40-45","40-45","40-45","40-50","40-50",null,null,null,null,null,"50-48"] const output = []; arrData.forEach(val => { if(output.indexOf(val) === -1 && val !== null) { output.push(val); } }); console.log(output);