angulartypescriptangular5angular6angular2-services

How to remove duplicate object from an array in angular 6


I am trying to remove duplicate value objects in an array but not working... I think duplicate function is working but not reflecting in li list. Can you find out where I have to change?

My service file:

 addComp(Names,c){   
 this.item.push({ name: Names, componentid: c});
 this.uniqueArray = this.removeDuplicates(this.item, "name"); //this line issue
 this.item=this.uniqueArray; //this line issue
 }

Solution

  • If addComp is the only place you modify this.item, just check for existing prior to insertion. Duplicates will never get put in the array, so you'll never have to trim them.

    addComp(Names,c){
      let item = {name: Names, componentid: c};
      if (this.item.find((test) => test.name === Names) === undefined) {
        this.item.push(item);
      }
    }
    

    Alternatively, if there are other places that you're modifying this.item, you should be stripping duplicates in a more expected place. Stripping them as a side-effect of the addComp function is unexpected. However, you could do it...

    addComp(Names,c){
      this.item.push({name: Names, componentid: c});
      this.item = this.item.filter((test, index, array) =>
         index === array.findIndex((findTest) =>
            findTest.name === test.name
         )
      );
    }