codewar ----- 累加

Given two integers ​​a​​​ and ​​b​​​, which can be positive or negative, find the sum of all the numbers between including them too and return it. If the two numbers are equal return ​​a​​​ or ​​b​​.

Note: ​​a​​​ and ​​b​​ are not ordered!

Examples

GetSum(1, 0) == 1   // 1 + 0 = 1
GetSum(1, 2) == 3   // 1 + 2 = 3
GetSum(0, 1) == 1   // 0 + 1 = 1
GetSum(1, 1) == 1   // 1 Since both are same
GetSum(-1, 0) == -1 // -1 + 0 = -1
GetSum(-1, 2) == 2  // -1 + 0 + 1 + 2 = 2

我的

function GetSum( a,b )
{
  var sum=0;
   if(a==b)
     return a;
    if(a<b)
    {
      for(var i=a;i<=b;i++)
        sum += i;
    }
    if(a>b)
    {
      for(var i=b;i<=a;i++)
        sum += i;
    }
    return sum;
}

others: