dart switch
Switch statements in Dart compare integer, string, or compile-time constants using ==. The compared objects must all be instances of the same class (and not of any of its subtypes), and the class must not override ==. Enumerated types work well in switch statements.
dart case
The switch statement takes the following form.
switch (variable) { case value1: // code break; case value2: // code break; default: // code }
- Based on the value of the variable in parentheses, which can be an int, String or compile-time constant, switch will redirect the program control to one of the case.
- Each case keyword takes a value and compares that value using
==
to the variable after the switch keyword.- The break keyword tells Dart to exit the switch statement.
- If none of the case values match the switch variable, then the code after default will be executed.
int number = 1; switch(number) { case 0: print('zero!'); break; // The switch statement must be told to exit, or it will execute every case. case 1: print('one!'); break; case 2: print('two!'); break; default: print('choose a different number!'); }
flutter switch case
Switch statements are great when there are many possible conditions for a single value.
- The default case is optional and All case expression must be unique.
- The case statements can include only constants. It cannot be a variable or an expression.
- There can be any number of case statements within a switch.
var grade = "A"; switch (grade) { case "A": print("Excellent"); break; case "B": print("Good"); break; case "C": print("Fair"); break; case "D": print("Poor"); break; default: print("Invalid choice"); break; }