如何将来自不同数组的两个独立对象转换为一个字符串？

Question

string[] groups;
int groupCount;
double[] grades;
int gradeCount;

So the groups and grades are in two separate arrays and I need to combine them as one string and add them to a new array.

string[] test = new string[groupCount];
for (int i = 0; i < groupCount; i++)
{
   test[i] = ("{0}:   {1}", groups[i], Math.Round(grades[i],2));              
   Console.WriteLine("{0}", test[i]);
}

How do i do it ?

Answer 1

C# 6.0 string interpolation (please, notice $ before the string):

test[i] = $"{groups[i]}:   {Math.Round(grades[i],2)}"; 

Another possibility is Linq (in order to output the entire collection in one go ):

string[] groups;
double[] grades;

...

var test = groups
  .Zip(grades, (group, grade) => $"{group}:    {Math.Round(grade, 2)}")
  .ToArray(); // array materialization (if you want just to output you don't need it)

Console.Write(String.Join(Environemnt.NewLine, test)); 

Answer 2

You forgot string.Format()

It should be,

string.Format("{0}:   {1}", groups[i], Math.Round(grades[i], 2));

Hope helps,