NumberOfVariables

Beschreibung

Die Funktion numberOfVariables zählt die Variablen in einem Ausdruck. Sie erwartet einen String und gibt einen numerischen Ausdruck zurück.

Syntax

numberOfVariables(Expression term)

Parameter

• term - der Ausdruck dessen Variablen gezählt werden sollen

Return Value

• Gibt einen numerischen Ausdruck zurück.

Beispiele

numberOfVariables('2x+3a-2b')    --> returns 3

JUnit Tests

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@Before 
public void beforeTest() {
  placeFillInVariable(1, OMParser.parse("0"));
  placeFillInVariable(2, OMParser.parse("3"));
  placeFillInVariable(5, OMParser.parse("x"));
		
  placeExerciseVariable("a", OMParser.parse("x"));
  placeExerciseVariable("b", OMParser.parse("3"));
}
	
@Test
public void testNumberOfVariables() {
  assertTrue(3 == getEvaluator().getNumberResult("numberOfVariables('2x+3a-x+2b')"));
  assertTrue(1 == getEvaluator().getNumberResult("numberOfVariables('2x+3x-x+2x')"));
		
  assertTrue(4 == getEvaluator().getNumberResult("numberOfVariables('sin(i)*E^(e)+ q/sqrt(s)')"));
  assertTrue(0 == getEvaluator().getNumberResult("numberOfVariables('5')"));
}
		
@Test
public void testNumberOfVariablesWithInput() {
  assertTrue(3 == getEvaluator().getNumberResult("numberOfVariables('2x+3a-x+2b')"));
  assertTrue(3 == getEvaluator().getNumberResult("numberOfVariables('2[pos=5]+3a-[pos=5]+2b')"));
  assertTrue(3 == getEvaluator().getNumberResult("numberOfVariables('2[pos=5]+3a-[pos=5]+2b')"));
  assertTrue(2 == getEvaluator().getNumberResult("numberOfVariables('2[pos=5]+3[pos=5]-[pos=5]+2b')"));
}
		
@Test
public void testNumberOfVariablesWithVariables() {	
  assertTrue(3 == getEvaluator().getNumberResult("numberOfVariables('2x+3a-x+2b')"));
  assertTrue(3 == getEvaluator().getNumberResult("numberOfVariables('2[var=a]+3a-[var=a]+2b')"));
  assertTrue(3 == getEvaluator().getNumberResult("numberOfVariables('2[var=a]+3a-[var=a]+2b')"));
  assertTrue(2 == getEvaluator().getNumberResult("numberOfVariables('2[var=a]+3[var=a]-[var=a]+2b')"));
}
	
@Test
public void testNumberOfVariablesWithONECharacter(){
  assertTrue(1 == getEvaluator().getNumberResult("numberOfVariables(a)"));
}
	
@Test(expected=InvalidCASFunctionArgumentException.class)
public void testNumberOfVariablesWithEmptyStringArguments(){
  getEvaluator().getNumberResult("numberOfVariables('')");
}
	
@Test(expected=InvalidCASFunctionArgumentException.class)
public void testNumberOfVariablesWithEmptyArgument(){
  getEvaluator().getNumberResult("numberOfVariables()");
}
	
@Test(expected=UndefinedExerciseVariableException.class)
public void testNumberOfVariablesWithMissingExerciseVariable(){
  getEvaluator().getNumberResult("numberOfVariables('[var=j]')");
}
	
@Test(expected=UndefinedFillInVariableException.class)
public void testNumberOfVariablesWithMissingInput(){
  getEvaluator().getNumberResult("numberOfVariables('[pos=42]')");
}