Question

Is there a difference in ++i and i++ in a for loop? Is it simply a syntax thing?

Answer 1

a++ is known as postfix.

add 1 to a, returns the old value.

++a is known as prefix.

add 1 to a, returns the new value.

C#:

string[] items = {'a','b','c','d'}; int i = 0; foreach (string item in items) {     Console.WriteLine(++i); } Console.WriteLine('');  i = 0; foreach (string item in items) {     Console.WriteLine(i++); } 

Output:

1 2 3 4  0 1 2 3 

foreach and while loops depend on which increment type you use. With for loops like below it makes no difference as you’re not using the return value of i:

for (int i = 0; i < 5; i++) { Console.Write(i);} Console.WriteLine(''); for (int i = 0; i < 5; ++i) { Console.Write(i); } 

0 1 2 3 4
0 1 2 3 4

If the value as evaluated is used then the type of increment becomes significant:

int n = 0; for (int i = 0; n < 5; n = i++) { }