Java method chaining

Question

I have a line of data that contains various non-delimited field values.

X55655PlateX58745CupX52689SaucerX52459SpoonH59876KnifeX59866Fork

I am trying to use substring and indexOf to pull the data, using a series of statements similar to the one below.

dataField1 = substring.inputLine((indexOf("Marker1: ")+9),(inputLine.indexOf("Marker2:")-1));

I keep getting error:cannot find symbol pointing to substring. Typically, this is when I've not called the proper java packages in, but I'm using the following:

import java.util.*;
import java.io.*;
import java.nio.file.*;
import java.lang.*;

and java.lang.* is where the string methods live, right? I'm also initializing String datafield1 = "";.

dataField1 = inputLine.Substring((indexOf("Marker1: ")+9),(indexOf("Marker2:")-1));

results in indexOf receiveing the cannot find symbnol error. But if indexOf is ALSO a method of String, where would that need to go?

My program appears to be using the proper syntax substring(x,y) as noted in the java documentation, however, there are no real-world examples applicable to my troubleshooting.

I've reviewed this article but it doesn't quite get me to wrap my head around the concepts any better.

Why dioes this keep erroring out, and how can I prevent it?

inputLine.Substring should have a lower case s for substring. i.e. inputLine.substring(... docs.oracle.com/javase/1.4.2/docs/api/java/lang/… — Jon Taylor
– Jon Taylor, Commented Jul 17, 2012 at 15:35
Generally, you don't need to import java.lang, as it's imported 'by default' (given it contains Object). But, isn't this a good case for actually using Pattern/Matcher (regex) combination? — Clockwork-Muse
– Clockwork-Muse, Commented Jul 17, 2012 at 15:39

Jon Taylor · Accepted Answer · 2012-07-17 15:26:53Z

7

substring should be called on a String object. Otherwise it is looking for a method called substring in your current class.

answered Jul 17, 2012 at 15:26

Jon Taylor

7,9255 gold badges32 silver badges55 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

hmjd · Accepted Answer · 2012-07-17 15:27:06Z

4

substring() is a method of String, should be:

inputLine.substring(...

assuming inputLine is a String instance.

answered Jul 17, 2012 at 15:27

hmjd

122k21 gold badges215 silver badges259 bronze badges

3 Comments

dwwilson66 Over a year ago

Thanks! When I do that, then indexOf becomes the unknown symbol. If indexOf is also a method of String...where would that need to go?

hmjd Over a year ago

@dwwilson66, inputLine.indexOf(), as usual already have following the first call.

Jon Taylor Over a year ago

You had it correct in your second use of indexOf just missed the inputLine. before the first call.

Anthony · Accepted Answer · 2012-07-18 02:01:10Z

0

Try this.

String dataField1 = inputLine.substring((inputLine.indexOf("Marker1: ")+9),
                                        (inputLine.indexOf("Marker2:")-1));

edited Jul 18, 2012 at 2:01

Anthony

12.4k10 gold badges72 silver badges107 bronze badges

answered Jul 17, 2012 at 15:28

nook

2,3965 gold badges34 silver badges54 bronze badges

3 Comments

Jon Taylor Over a year ago

you ought to explain why what you are doing makes the code valid rather than just rewriting code. This helps the OP to understand what he/she was doing wrong.

dwwilson66 Over a year ago

@publ1c_stat1c Actually...I think I see it...because substring and indexOf are both methods of String, I need to call them from my string in both instances: inputline.substring AND inputline.indexOf. Is that a correct statement?

Jon Taylor Over a year ago

Yes that is correct. Methods must be called on the object otherwise it looks for the method defined in your class. Since substring is not a method in your class it cannot find the symbol

Collectives™ on Stack Overflow

Java method chaining

3 Answers 3

Comments

3 Comments

3 Comments

Linked

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

3 Comments

3 Comments

Linked

Related