Syntax error on token "-", invalid AssignmentOperator

Question

for (int iI = 4; iI > 0; iI--)
  faAmount[iI] - faAmount[iI - 1];

This is the code it's in. How can I fix this?

Solution 1

Maybe you forgot the equal sign

for (int iI = 4; iI > 0; iI--) 
    faAmount[iI] -= faAmount[iI - 1];

Or to assign the difference in a variable

double x = 0; //or another value
for (int iI = 4; iI > 0; iI--) 
    x = faAmount[iI] - faAmount[iI - 1];

Solution 2

faAmount[iI] - faAmount[iI - 1] is n expression that have a result, but you don't assign it to anything, this is invalid in Java.

Solution 3

The technical explanation is that faAmount[iI] - faAmount[iI - 1] is an expression but isn't a statement. The JLS notes that

Unlike C and C++, the Java programming language allows only certain forms of expressions to be used as expression statements.

An additive expression is not one of those expressions that are also statements.