Substring (Jep with extensions API )

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

Field Summary
- Fields inherited from class com.singularsys.jep.functions.PostfixMathCommand
  curNumberOfParameters, name, NaN, numberOfParameters

Constructor Summary

Constructors
Constructor Description

Substring()

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`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, getName, getNumberOfParameters, setCurNumberOfParameters, setName, toString, toString

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Constructor Detail
  - Substring
```
public Substring()
```
- Method Detail
  - 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 - if the calculation cannot be performed