Use: h.className = h.className + (h.className ? ‘ error’ : ‘error’) You want the operator to work for h.className. Better be specific about it. Of course, no harm should come from h.className += ‘ error’, but that’s another matter. Also, note that + has precedence over the ternary operator: JavaScript Operator Precedence
Reason The operators &&= and ||= are not available on Java because for most of the developers these operators are: error-prone useless Example for &&= If Java allowed &&= operator, then that code: bool isOk = true; //becomes false when at least a function returns false isOK &&= f1(); isOK &&= f2(); //we may expect … Read more
The |= is a compound assignment operator (JLS 15.26.2) for the boolean logical operator | (JLS 15.22.2); not to be confused with the conditional-or || (JLS 15.24). There are also &= and ^= corresponding to the compound assignment version of the boolean logical & and ^ respectively. In other words, for boolean b1, b2, these … Read more
That’s because b += 1.0; is equivalent to b = (int) ((b) + (1.0));. The narrowing primitive conversion (JLS 5.1.3) is hidden in the compound assignment operation. JLS 15.26.2 Compound Assignment Operators (JLS Third Edition): A compound assignment expression of the form E1 op= E2 is equivalent to E1 = (T)((E1) op (E2)), where T … Read more
In Python, += is sugar coating for the __iadd__ special method, or __add__ or __radd__ if __iadd__ isn’t present. The __iadd__ method of a class can do anything it wants. The list object implements it and uses it to iterate over an iterable object appending each element to itself in the same way that the … Read more
h.className = h.className + (h.className ? ‘ error’ : ‘error’) You want the operator to work for h.className, better be specific about it. Of course, no harm should come from h.className += ‘ error’, but that’s another matter. Also, note that + has precedence over the ternary operator: JavaScript Operator Precedence