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Thread: Insert != null check issues

  1. #1
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    Default Insert != null check issues

    I am making something that turns a string into an Integer if it is an Integer, or keeps it as a String if it is a String. I have that bit working fine, it is just when I try and check to see what the String is (if it is a string) I get Eclipse saying I have to insert != null because I am converting a boolean into a string. The thing is, if I click on it, it just makes more errors.

    Here is my code:

    import java.io.*;
     
     
    public class gplReader {
     
    	//Class variables
    	files f = new files();
     
    	//General Variables
    	boolean nextIsInt;
     
    	public gplReader(){
     
    	}
     
    	public void startRead(String name) throws IOException{
    		try{
    			System.out.println("Reading File");
    			String[] aryLines = f.readFileData("gpl/" + name);
     
    			System.out.println("Reading Data");
    			int i;
     
    			for(i=0; i<aryLines.length; i++){
    				System.out.println("Printing line" + " " + (i+1) + " ");
    				System.out.println(aryLines[i]);
    				System.out.println("Interpreting line" + " " + (i+1) + "");
    				interpretGpl(aryLines[i]);
    			}
    		} finally {
    			System.out.println("\nFinished Printing Lines\n");
    		}
    	}
     
    	public void interpretGpl(String aryLines){
     
    		String line = aryLines;
    		String[] tempString = null;
    		int[] tempInt = null;
    		int i = 0;
    		boolean isInt;
    		boolean storeValue = false;
     
    		try{
    			Integer.parseInt(line);
    			System.out.println("Line is Integer" + "\n");
    			isInt = true;
    			if(isInt != false){
    				tempInt[i] = Integer.parseInt(line);
    			}
     
    		} catch (Exception ex){
    			System.out.println("Line isn't an Integer" + "\n");
    			isInt = false;
    			if(isInt != true){
    				tempString[i] = line;
    			}
    		}
     
    		if(isInt != true){
    			if(tempString[i] != null){
    				----if(tempString[0] = "printf"){----
     
    				}
    			}
    		}
     
    	}
     
    }

    The line of code surrounded by ---- is the bit that is throwing up errors.

    Hope you can help.


  2. #2
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    Default Re: Insert != null check issues

    Hello JamEngulfer221!
    if(tempString[0] = "printf")
    The above statement is an assignment; you assign "printf" to tempString[0]. I think that instead of this assignment you want to compare them. Therefore you need to use the String's equals() method (instead of the == operator), since they are Strings.
    Hope it helps.

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    Default Re: Insert != null check issues

    No... No... There's no way I could have done that... Wow. I can't believe the absolute stupidity of what I did. I just can't believe it. Well, great. Thanks for the help though!

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    Default Re: Insert != null check issues

    Don't feel that way, evereybody is making that kind of errors at times.
    And something else I noticed.
    You should initialize an array before you try to assign a value to an index of it otherwise a NullPointerException will be thrown.

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