使用for循环时如何删除最后一个逗号？

Question

I have to display a message after performing validation saying that the Nationality- A,B,C already exists.

预期消息：国籍 - A、B、C 已经存在。

我现在收到的实际消息是：国籍 - A、B、C 已经存在。 (需要去掉C后面的逗号)

if(error.status === 409){
  this._commonSrvc.error('Nationality- '+this.getNationality(payLoad.custBkgGrpNationality) +' already exists +'.');
        return;
      }



private getNationality(Nationalities:any)
  { let Nationalitiesstr : String ="";
    for(let i=0; i<Nationalities.length; i++)
    {
      Nationalitiesstr = Nationalitiesstr + this.nationalityData.find(x => x.libraryID == Nationalities[i].nationalityXid).libraryName + ',';
    }
    return Nationalitiesstr; 
  }

Answer 1

去掉字符串末尾的逗号。然后添加检查以查看 i 是否小于集合长度 - 1。类似...

Nationalitiesstr = Nationalitiesstr + this.nationalityData.find(x => x.libraryID == Nationalities[i].nationalityXid).libraryName;

if (i < Nationalities.length -1)
  Nationalitiesstr += “, “;

String.Join Method …也可能有效。

使用for循环时如何删除最后一个逗号？

How to remove the last comma when using for loop?

.net

for-loop

angularjs

angular