com.singularsys.jep.functions.strings
Class Substring
java.lang.Object
com.singularsys.jep.functions.PostfixMathCommand
com.singularsys.jep.functions.NaryFunction
com.singularsys.jep.functions.strings.Substring
- All Implemented Interfaces:
- PostfixMathCommandI, java.io.Serializable
public class Substring
- extends NaryFunction
Extract substring of first argument: substring("abcdefg",2,4) -> "cd".
Syntax substring(str,start,[end])
.
Second argument is starting index,
third argument is optional, if not present return rest of string
if present third argument is the ending index, exclusive.
Note that the indices are zero-based.
- If
start
is greater than the length of the string an EvaluationException is thrown.
- If
start
is less than zero an EvaluationException is thrown.
- If
end
is less than start an EvaluationException is thrown.
- If
end
is greater than the length of the string an EvaluationException is thrown.
- If
str
is not a string an EvaluationException is thrown.
If start
is not a number representing an integer an EvaluationException is thrown.
If end
is not a number representing an integer an EvaluationException is thrown.
- See Also:
String.substring(int, int)
,
Serialized Form
Method Summary |
boolean |
checkNumberOfParameters(int n)
Checks the number of parameters of the function. |
java.lang.Object |
eval(java.lang.Object[] args)
Evaluate the function |
Methods inherited from class com.singularsys.jep.functions.NaryFunction |
run |
Methods inherited from class com.singularsys.jep.functions.PostfixMathCommand |
asArray, asBool, asDouble, asInt, asLong, asStrictInt, asString, checkStack, getName, getNumberOfParameters, setCurNumberOfParameters, setName, toString |
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Substring
public Substring()
checkNumberOfParameters
public boolean checkNumberOfParameters(int n)
- Description copied from class:
PostfixMathCommand
- Checks the number of parameters of the function.
Functions which set numberOfParameter=-1 should overload this method
- Specified by:
checkNumberOfParameters
in interface PostfixMathCommandI
- Overrides:
checkNumberOfParameters
in class PostfixMathCommand
- Parameters:
n
- number of parameters function will be called with.
- Returns:
- false if an illegal number of parameters is supplied, true otherwise.
eval
public java.lang.Object eval(java.lang.Object[] args)
throws EvaluationException
- Description copied from class:
NaryFunction
- Evaluate the function
- Specified by:
eval
in class NaryFunction
- Parameters:
args
- arguments to the function
- Returns:
- value returned by the function
- Throws:
EvaluationException
Copyright © 2010 Singular Systems http://www.singularsys.com/jep