> a[i]=a[i++]; I read this as saying assign to the array a's position i, the value stored in array a's position i, and then increment i. In code this would be a[i] = a[i]; i++; > Looks like gcc is treating this as a[i]=a[i];i++; Where as the > programmers intention could be a[i+1]=a[i];i++; The programmers intention could never be that unless they really are not sure about prefix / postfix notation and the usage of arrays. There are subtle differences: A) Assign to array a's position i, the value stored in array a at position i, then increment i. B) Assign to array a's position i+1 the value of array a at position i, then inc i. > Does the C language ANSI standard enforce any evaluation order or the > implementation is left to the compiler? i++ will increase i after any other operation on the line is complete ++i will increase i and then perform the other operations. Note you cannot just issue : a[i] = a[++i]; either though, as the new position i (ie i+1) will be used for both the assigned value position and the read.
