How to write on other values placed after the operators case?

Question

Good afternoon, I am using the switch construction, but I don’t know how to write correctly for other values after the case operators.

In the DisplayData code, in the swi

Answer 1

The problem is default:.

The switch run like this: it finds the case which corresponds to the key and starts executing code from this point on until it hits a break;. The default: case is a catch-all: it'll like a condition which would always be true.

To illustrate, I like this example: here when the user enters a number, it prints to the console the names of all the month from that point up to December.

int month = 5;

switch (month) {
    case 1:  println("January");
    case 2:  println("February");
    case 3:  println("March");
    case 4:  println("April");
    case 5:  println("May");
    case 6:  println("June");
    case 7:  println("July");
    case 8:  println("August");
    case 9:  println("September");
    case 10: println("October");
    case 11: println("November");
    case 12: println("December");
             break;
    default: println("Error: no valid month selected.");
             break;
}

Notice how default is at the end. That's because since it's always "true" and since the switch will select only one case and then run until a break statement, if I put it anywhere else it will always be selected when it's read. See by modifying the example like this:

int month = 5;

switch (month) {
    default: println("Whatever, I'm not printing month anymore!");
             break; // no case after this point will ever be read
    case 1:  println("January");
    case 2:  println("February");
    case 3:  println("March");
    case 4:  println("April");
    case 5:  println("May");
    case 6:  println("June");
    case 7:  println("July");
    case 8:  println("August");
    case 9:  println("September");
    case 10: println("October");
    case 11: println("November");
    case 12: println("December");
             break;
}

This is exactly what happens in your program. In DisplayData(), right at tthe beginning there's a default case which overrides all the other cases:

void Displaydata() {

  switch(readIncome[0]) {
  case 10:
  default: // <--- HERE THIS IS ALWAYS SELECTED
    minutess.setCaptionLabel(readIncome[1]+" Мин.");
    min=readIncome[1];
    break; // <--- EVERYTHING AFTER THIS IS IGNORED

You can re-write with the correct syntax like this:

void Displaydata() {
  switch(readIncome[0]) {
  case 10:
    minutess.setCaptionLabel(readIncome[1]+" Мин.");
    min=readIncome[1];
    break;
  case 20:
    button.label(readIncome[1]+" Мин."); //ImageButton
    min=readIncome[1];
    break;
  case 30:
    if(readIncome[1]==1)P4.setText("on");
    if(readIncome[1]==0)P4.setText("off");// CheckBox
    break;
  case 40:
    inputPULI.setText("Bullet - "+readIncome[1] ); //Numberbox int
    break;
  case 70:
    inputNapryzenieKV.setText("Voltage - "+readIncome[1] ); //Numberbox float
    break;
  case 60:
    Vin.setText("Voltage K.V - "+readIncome[1] );
    break;
  case 50:
    if(readIncome[1]==1)CheckBoxuvum.setText("+"); //RadioButton
    if(readIncome[1]==0)CheckBoxuvum.setText("-");
    break;
  default:
    println("DisplayData(): no case selected.");
    break; // technically not necessary, but I like my switches tidy
  }
}

Have fun!