What are the pros/cons (if any) to usingstring output; int i = 10;output = string.Format(the int is {0}, i);versusstring output; int i = 10;output = the int is  + i;I have always used the latter example, but it seems as though a good majority of online tutorials use the string.format example. I don't think that there are any real differences in terms of efficiency, my initial thought is so a coder doesn't have to keep breaking the string to insert variables. 
string.format with variables vs inline variables
c#;.net;vb.net;strings
If you consider translation to be important in your project, the first syntax will really help with it. For instance you may have:static final string output_en = {0} is {1} year's old.;static final string output_fr = {0} a {1} ans.;int age = 10;string name = Henri;System.out.println(string.Format(output_en, age, name));System.out.println(string.Format(output_fr, age, name));Also note that your variables may not always be in the same place in the sentence with that syntax:static final string output_yoda = {1} years {0} has.;