About variables in Loop

[Andry Dub]

What is wrong with my code?

for(int m=0,n=0;m<5;(m++)++) {
System.out.print(m + " ");
}

[Kelvin Chenhao Lim]

Hi Andry,

"(m++)++" is not valid Java syntax, even when it's not part of a loop. The ++ operator must always operate on an assignable variable (or what people sometimes call an "lvalue"). "m++" is not an assignable variable, which means you cannot write a statement like "m++ = 5". "m++" by itself is fine, but this evaluates to an integer value--and you cannot use ++ on a raw integer value (i.e. you can't write "2++").

To achieve what you seem to be trying to do, use something like this instead:

for(int m=0,n=0;m<5;m+=2) {
  System.out.print(m + " ");
}

[Andry Dub]

Thank you very much for your interesting reply!