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33 lines
961 B
33 lines
961 B
2 years ago
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# Optional Sum
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### Instructions
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Write a function called `optionalSum()` that accepts two integer arguments, and an optional integer argument. Return the sum of all the arguments.
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### Optional parameters
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In Dart you can also make function arguments optional, meaning that a function can work even if the optional argument is omitted. If the optional parameter is omitted, it is considered to be null.
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### Usage
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Example of function with optional parameters:
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```dart
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void someFunction(int firstParameter, int secondParameter, [int? optionalParameter]) {
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if (optionalParameter != null) {
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print('${firstParameter}, ${secondParameter}, ${optionalParameter}');
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} else {
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print('${firstParameter}, ${secondParameter}');
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}
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}
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void main() {
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someFunction(1, 2);
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someFunction(1, 2, 3);
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}
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```
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- Note: Optional parameters must come after the required parameters.
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- Note: You cannot use both optional and named parameters, you should choose only one of them.
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