Java: Get last element after split

I am using the String split method and I want to have the last element. The size of the Array can change.

Example:

String one = "Düsseldorf - Zentrum - Günnewig Uebachs"
String two = "Düsseldorf - Madison"

I want to split the above Strings and get the last item:

lastone = one.split("-")[here the last item] // <- how?
lasttwo = two.split("-")[here the last item] // <- how?

I don't know the sizes of the arrays at runtime :(

You could use lastIndexOf() method on String

String last = string.substring(string.lastIndexOf('-') + 1);

Save the array in a local variable and use the array's length field to find its length. Subtract one to account for it being 0-based:

String[] bits = one.split("-");
String lastOne = bits[bits.length-1];

Caveat emptor: if the original string is composed of only the separator, for example "-" or "---", bits.length will be 0 and this will throw an ArrayIndexOutOfBoundsException. Example: https://onlinegdb.com/r1M-TJkZ8

You can use the StringUtils class in Apache Commons:

StringUtils.substringAfterLast(one, "-");

using a simple, yet generic, helper method like this:

public static <T> T last(T[] array) {
    return array[array.length - 1];
}

you can rewrite:

lastone = one.split("-")[..];

as:

lastone = last(one.split("-"));

String str = "www.anywebsite.com/folder/subfolder/directory";
int index = str.lastIndexOf('/');
String lastString = str.substring(index +1);

Now lastString has the value "directory"

Gathered all possible ways together!!

---

By using lastIndexOf() & substring() methods of Java.lang.String

// int firstIndex = str.indexOf( separator );
int lastIndexOf = str.lastIndexOf( separator );
String begningPortion = str.substring( 0, lastIndexOf );
String endPortion = str.substring( lastIndexOf + 1 );
System.out.println("First Portion : " + begningPortion );
System.out.println("Last  Portion : " + endPortion );

---

split()^{Java SE 1.4}. Splits the provided text into an array.

String[] split = str.split( Pattern.quote( separator ) );
String lastOne = split[split.length-1];
System.out.println("Split Array : "+ lastOne);

• How to split String before first comma?

---

Java 8 sequential ordered stream from an array.

String firstItem = Stream.of( split )
						 .reduce( (first,last) -> first ).get();
String lastItem = Stream.of( split )
						.reduce( (first,last) -> last ).get();
System.out.println("First Item : "+ firstItem);
System.out.println("Last  Item : "+ lastItem);

---

Apache Commons Lang^jar « org.apache.commons.lang3.StringUtils

String afterLast = StringUtils.substringAfterLast(str, separator);
System.out.println("StringUtils AfterLast : "+ afterLast);

String beforeLast = StringUtils.substringBeforeLast(str, separator);
System.out.println("StringUtils BeforeLast : "+ beforeLast);

String open = "[", close = "]";
String[] groups = StringUtils.substringsBetween("Yash[777]Sam[7]", open, close);
System.out.println("String that is nested in between two Strings "+ groups[0]);

---

Guava: Google Core Libraries for Java. « com.google.common.base.Splitter

Splitter splitter = Splitter.on( separator ).trimResults();
Iterable<String> iterable = splitter.split( str );
String first_Iterable = Iterables.getFirst(iterable, "");
String last_Iterable = Iterables.getLast( iterable );
System.out.println(" Guava FirstElement : "+ first_Iterable);
System.out.println(" Guava LastElement  : "+ last_Iterable);

---

Scripting for the Java Platform « Run Javascript on the JVM with Rhino/Nashorn

• Rhino « Rhino is an open-source implementation of JavaScript written entirely in Java. It is typically embedded into Java applications to provide scripting to end users. It is embedded in J2SE 6 as the default Java scripting engine.

• Nashorn is a JavaScript engine developed in the Java programming language by Oracle. It is based on the Da Vinci Machine and has been released with Java 8.

Java Scripting Programmer's Guide

public class SplitOperations {
	public static void main(String[] args) {
		String str = "my.file.png.jpeg", separator = ".";
		javascript_Split(str, separator);
	}
	public static void javascript_Split( String str, String separator ) {
		ScriptEngineManager manager = new ScriptEngineManager();
		ScriptEngine engine = manager.getEngineByName("JavaScript");
		
		// Script Variables « expose java objects as variable to script.
		engine.put("strJS", str);
		
		// JavaScript code from file
		File file = new File("E:/StringSplit.js");
		// expose File object as variable to script
		engine.put("file", file);
		
		try {
			engine.eval("print('Script Variables « expose java objects as variable to script.', strJS)");
			
			// javax.script.Invocable is an optional interface.
			Invocable inv = (Invocable) engine;
			
			// JavaScript code in a String
			String functions = "function functionName( functionParam ) { print('Hello, ' + functionParam); }";
			engine.eval(functions);
			// invoke the global function named "functionName"
			inv.invokeFunction("functionName", "function Param value!!" );
			
			// evaluate a script string. The script accesses "file" variable and calls method on it
			engine.eval("print(file.getAbsolutePath())");
			// evaluate JavaScript code from given file - specified by first argument
			engine.eval( new java.io.FileReader( file ) );
			
			String[] typedArray = (String[]) inv.invokeFunction("splitasJavaArray", str );
			System.out.println("File : Function returns an array : "+ typedArray[1] );
			
			ScriptObjectMirror scriptObject = (ScriptObjectMirror) inv.invokeFunction("splitasJavaScriptArray", str, separator );
			System.out.println("File : Function return script obj : "+ convert( scriptObject ) );
			
			Object eval = engine.eval("(function() {return ['a', 'b'];})()");
			Object result = convert(eval);
			System.out.println("Result: {}"+ result);
			
			// JavaScript code in a String. This code defines a script object 'obj' with one method called 'hello'.
			String objectFunction = "var obj = new Object(); obj.hello = function(name) { print('Hello, ' + name); }";
			engine.eval(objectFunction);
			// get script object on which we want to call the method
			Object object = engine.get("obj");
			inv.invokeMethod(object, "hello", "Yash !!" );
			
			Object fileObjectFunction = engine.get("objfile");
			inv.invokeMethod(fileObjectFunction, "hello", "Yashwanth !!" );
		} catch (ScriptException e) {
			e.printStackTrace();
		} catch (NoSuchMethodException e) {
			e.printStackTrace();
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		}
	}

	public static Object convert(final Object obj) {
		System.out.println("\tJAVASCRIPT OBJECT: {}"+ obj.getClass());
		if (obj instanceof Bindings) {
			try {
				final Class<?> cls = Class.forName("jdk.nashorn.api.scripting.ScriptObjectMirror");
				System.out.println("\tNashorn detected");
				if (cls.isAssignableFrom(obj.getClass())) {
					final Method isArray = cls.getMethod("isArray");
					final Object result = isArray.invoke(obj);
					if (result != null && result.equals(true)) {
						final Method values = cls.getMethod("values");
						final Object vals = values.invoke(obj);
						System.err.println( vals );
						if (vals instanceof Collection<?>) {
							final Collection<?> coll = (Collection<?>) vals;
							Object[] array = coll.toArray(new Object[0]);
							return array;
						}
					}
				}
			} catch (ClassNotFoundException | NoSuchMethodException | SecurityException
					| IllegalAccessException | IllegalArgumentException | InvocationTargetException e) {
			}
		}
		if (obj instanceof List<?>) {
			final List<?> list = (List<?>) obj;
			Object[] array = list.toArray(new Object[0]);
			return array;
		}
		return obj;
	}
}

JavaScript file « StringSplit.js

// var str = 'angular.1.5.6.js', separator = ".";
function splitasJavaArray( str ) {
  var result = str.replace(/\.([^.]+)$/, ':$1').split(':');
  print('Regex Split : ', result);
  var JavaArray = Java.to(result, "java.lang.String[]");
  return JavaArray;
  // return result;
}
function splitasJavaScriptArray( str, separator) {
	var arr = str.split( separator ); // Split the string using dot as separator
	var lastVal = arr.pop(); // remove from the end
	var firstVal = arr.shift(); // remove from the front
	var middleVal = arr.join( separator ); // Re-join the remaining substrings

	var mainArr = new Array();
	mainArr.push( firstVal ); // add to the end
	mainArr.push( middleVal );
	mainArr.push( lastVal );
	
	return mainArr;
}

var objfile = new Object();
objfile.hello = function(name) { print('File : Hello, ' + name); }

• JavaScript Array constructor or array literal.

With Guava:

final Splitter splitter = Splitter.on("-").trimResults();
assertEquals("Günnewig Uebachs", Iterables.getLast(splitter.split(one)));
assertEquals("Madison", Iterables.getLast(splitter.split(two)));

Splitter, Iterables

Since he was asking to do it all in the same line using split so i suggest this:

lastone = one.split("-")[(one.split("-")).length -1]  

I always avoid defining new variables as far as I can, and I find it a very good practice

You mean you don't know the sizes of the arrays at compile-time? At run-time they could be found by the value of lastone.length and lastwo.length .

Also you can use java.util.ArrayDeque

String last = new ArrayDeque<>(Arrays.asList("1-2".split("-"))).getLast();

In java 8

String lastItem = Stream.of(str.split("-")).reduce((first,last)->last).get();

I guess you want to do this in i line. It is possible (a bit of juggling though =^)

new StringBuilder(new StringBuilder("Düsseldorf - Zentrum - Günnewig Uebachs").reverse().toString().split(" - ")[0]).reverse()

tadaa, one line -> the result you want (if you split on " - " (space minus space) instead of only "-" (minus) you will loose the annoying space before the partition too =^) so "Günnewig Uebachs" instead of " Günnewig Uebachs" (with a space as first character)

Nice extra -> no need for extra JAR files in the lib folder so you can keep your application light weight.