For loop increment question

Projects Programming
1

Why is it when you want to increment by one, it's variable++ but if you want to increment by other value, you have to spell it out fully like variable = variable +2? Why can't I just do a straight variable + 2 in the for loop?

for (int x = 0; x<y; x++)

works fine

for (int x = 0; x<y; x+2)

doesn't work

for (int x = 0; x<y; x = x +2)

works?

2 
for (int x = 0; x<y; x+=2)
3

You can also use this style

for (int x = 0; x<y; x +=2)

...R

4

Why can't I just do a straight variable + 2 in the for loop?

The pre and post increment/decrement operators have an implicit reassignment.

'x + y' has no such reassignment.

5

They are just shorthand notations:

// these lines all increment by one:
i++;
i+=1;
i=i+1;

// these lines increment by two:
i+=2;
i=i+2;
6

TimMJN:
They are just shorthand notations:

i think it's in C because the DEC processor C was developed on had in/decrement machine instructions.

of course it seems obvious to have such an operation in any language, just as it was to the DEC processor architects