Question

string nr = "42245555" //just an example number
string expression = "{5}{6}/{7}{8}";

string res = String.Format(expression, new string[] {
nr[0].ToString(),nr[1].ToString(),
nr[2].ToString(), nr[3].ToString(), 
nr[4].ToString(), nr[5].ToString(), 
nr[6].ToString(), nr[7].ToString() 
});

Why is this not working and how can I solve it?
I want expression to be either "{5}{6}/{7}{8}" or "{0}{3}/{7}{1}" or whatever the user wants.

Answer 1

The parameters in expression must start from "{0}" and the array must contain the same number of parameters as the expression and it must be an array of objects : new object[]{...