对象数组，如果key中的value相同，不要该项

<script type="text/javascript">

  

let arr=[

{

gradeId: "498094709437239572",

gradeName: "2018级",

stageId: "2",

stageName: "初中",

},

{

gradeId: "498094709437239572",

gradeName: "2018级",

stageId: "2",

stageName: "初中1",

},

{

gradeId: "498094709437239572",

gradeName: "2018级",

stageId: "2",

stageName: "初中2",

},

{

gradeId: "498094709437239572",

gradeName: "2018级",

stageId: "2",

stageName: "初中1",

},

{

gradeId: "498094709437239572",

gradeName: "2018级",

stageId: "2",

stageName: "初中3",

},

]

// 先找出不同的阶段，对象数组，如果key中的value相同，不要该项

let newArr=[]

let lastUseArr=[];

for(let i=0;i<arr.length;i++){

if(newArr.indexOf(arr[i].stageName)==-1){

newArr.push(arr[i].stageName)

lastUseArr.push(arr[i])

}

}

console.log(lastUseArr)

  

</script>