id is of primitive type int and not an Object. You cannot call methods on a primitive as you are doing here : Try replacing this: if (id.equals(list[pos].getItemNumber())){ //Getting error on “equals” with if (id == list[pos].getItemNumber()){ //Getting error on “equals”
When you convert double to int,the precision of the value is lost. For example, When you convert 4.8657 (double) to int.The int value will be 4.Primitive int does not store decimal numbers.So you will lose 0.8657. In your case,0.7 is a double value(floating point treated as double by default unless mentioned as float-0.7f). When you calculate price*much*0.7 ,the answer is a double … Read more
How can I prevent java.lang.NumberFormatException: For input string: “N/A”?
Use a DecimalFormatter: double number = 0.9999999999999; DecimalFormat numberFormat = new DecimalFormat(“#.00”); System.out.println(numberFormat.format(number)); Will give you “0.99”. You can add or subtract 0 on the right side to get more or less decimals. Or use ‘#’ on the right to make the additional digits optional, as in with #.## (0.30) would drop the trailing 0 to … Read more
An int is not null, it may be 0 if not initialized. If you want an integer to be able to be null, you need to use Integer instead of int. Integer id; String name; public Integer getId() { return id; } Besides the statement if(person.equals(null)) can’t be true, because if person is null, then a NullPointerException will be thrown. So the correct expression is if (person == null)
How to check whether a int is not null or empty?
int is a primitive type. Variables of type int store the actual binary value for the integer you want to represent. int.parseInt(“1”) doesn’t make sense because int is not a class and therefore doesn’t have any methods. Integer is a class, no different from any other in the Java language. Variables of type Integer store references to Integer objects, just as with any other reference (object) type. Integer.parseInt(“1”) is a call to the … Read more
Java, Simplified check if int array contains int
JAVA Variable declaration not allowed here
You could use this to sort all kind of Objects sort(T[] a, Comparator<? super T> c) Arrays.sort(a, Collections.reverseOrder()); Arrays.sort() cannot be used directly to sort primitive arrays in descending order. If you try to call the Arrays.sort() method by passing reverse Comparator defined by Collections.reverseOrder() , it will throw the error no suitable method found for sort(int[],comparator) That will work … Read more
