Why is i++ used instead of ++i in array for loops

[swarali57778]

hey i wna know that y we usei++ instead of ++i in array proegram for loops

[weaknessforcats]

Using i++ is less efficient than ++i.

The reason is that ++i immediately increments the variable whereas i++ makes a copy of the variable and increments the copy. So i++ is slower by the amount of time required to make that copy.

Example:

int i = 10;
 
if (i++ == 11)   //here i is 10. It won't be 11 until the next statement
{
}
int j = 10;   
 
if (++j == 11)   //here j is 11
{
 
}
 

If you are just incrementing a variable as in a loop then either i++ or ++i will work because you are not testing the variable but only incrementing it. Good programming will use ++i in these situations.

[donbock]

@weaknessforcats: should line 3 be i++?

Either form of autoincrement can be used in loops. i++ typically indicates that i enters the statement with the value to use in this iteration and exits the statement with the value to use in the next iteration. ++i typically indicates that i enters the statement with value used in the previous iteration and exits the statement with the value used in this iteration. These are generalities -- it would be pretty easy to provide examples that violate these statements.

[weaknessforcats]

Yes it should. I fixed the line.