Cannot find symbol parseInt

[thejwal pavithran]

class Parse
{
	public static void main(String[] args)
	{
		int num=Integer.parseInt(args);

	}
}

hey guys,
when i compile the above program, i get the error that Cannot find symbol method parseInt()..please help me..

[Ashwin Sridhar]

What is the JDK version that you are using.

[Winston Gutkowski]

thejwal pavithran wrote:when i compile the above program, i get the error that Cannot find symbol method parseInt()..please help me..

What type is 'args', and what type does Integer.parseInt() take as its parameter?

Winston

[thejwal pavithran]

in java folder there is jdk1.6.0_18 and jre6 and jre7

[Ashwin Sridhar]

You are trying to pass a array as parameter to Integer.parseInt(), but you should actually pass a String Object.

[thejwal pavithran]

Winston Gutkowski wrote:

thejwal pavithran wrote:when i compile the above program, i get the error that Cannot find symbol method parseInt()..please help me..

What type is 'args', and what type does Integer.parseInt() take as its parameter?

Winston

in the java documentation i have, it says:
it is a static public memeber of Integer class
parseInt(String s)
Parses the string argument as a signed decimal integer.

[thejwal pavithran]

Ashwin Sridhar wrote:You are trying to pass a array as parameter to Integer.parseInt(), but you should actually pass a String Object.

oh i get it... in java, a string array contains references to the string objects and not the strings themselves so i shud use args[0]??let me try it

[Jeff Verdegan]

thejwal pavithran wrote:

Winston Gutkowski wrote:

thejwal pavithran wrote:when i compile the above program, i get the error that Cannot find symbol method parseInt()..please help me..

What type is 'args', and what type does Integer.parseInt() take as its parameter?

Winston

in the java documentation i have, it says:
it is a static public memeber of Integer class
parseInt(String s)
Parses the string argument as a signed decimal integer.

But you're not passing it a String. Hence the error.

[Jeff Verdegan]

thejwal pavithran wrote:

Ashwin Sridhar wrote:You are trying to pass a array as parameter to Integer.parseInt(), but you should actually pass a String Object.

oh i get it... in java, a string array contains references to the string objects and not the strings themselves

No variable ever contains an object in Java. Array variables are not special in that sense. A variable contains a primitive, a reference, or null. A String variable contains a reference to a String object. A String[] variable contains a reference to a String[] object, which in turn contains references to String objects.

so i shud use args[0]??let me try it

If you want to parse the first arg that was passed, yes.

[thejwal pavithran]

so how wud i read ints during run time? like scanf or cin?

[Ashwin Sridhar]

You could have your numbers passed in as a part of arguements in command line. But it would be passed as String and you could convert it into int as you do.

Assume you call your testClass.java and pass 10 as input in command line.

you will do a ,

 java testClass 10

This 10 would be passed as a String and would be first element in the array args.

So, you convert into int as ,

 int a = Integer.parseInt(args[0])

Remember if you pass anything other than int and try to convert, you will get a NumberFormatException.

[Winston Gutkowski]

thejwal pavithran wrote:so how wud i read ints during run time? like scanf or cin?

First: Please UseRealWords (←click). This isn't an SMS message.

Second: There's nothing to stop you from piping input to a Java program. On the other hand, things like scanf() are methods, not programs; and cin is a stream, and it's equivalent in Java is System.in.

Winston

[thejwal pavithran]

Ashwin Sridhar wrote:You could have your numbers passed in as a part of arguements in command line. But it would be passed as String and you could convert it into int as you do.

Sir if i want to write like

System.out.println("PLEASE ENTER YOUR NUMBER ");

Then how will I read the value entered by user into an int variable?i am looking for something like cin or scanf

[Ashwin Sridhar]

Then you should use System.in . Look this doc

[thejwal pavithran]

Ashwin Sridhar wrote:Then you should use System.in . Look this doc

thank you.

[Jesper de Jong]

thejwal pavithran wrote:Then how will I read the value entered by user into an int variable?i am looking for something like cin or scanf

Class java.util.Scanner would be good for that. Look at the API documentation for that class - it has an example for exactly what you want to do.