How to convert a string to a number

[chirs]

Hi,

How to convert a string such as "1,000" to a number? I tried
Integer.parseInt("1,000");. But it did not work.

Thank you.

Chris

 

[Dave Miller]

Hi,

How to convert a string such as "1,000" to a number? I tried
Integer.parseInt("1,000");. But it did not work.

Thank you.

Chris

Look at java.text.NumberFormat - it can handle extraneous input like
commas, monetary symbols, etc.

 

[Sudsy]

Hi,

How to convert a string such as "1,000" to a number? I tried
Integer.parseInt("1,000");. But it did not work.

Thank you.

Chris

Not surprising that it didn't work. Commas as part of the number don't
generally reflect how computers deal with numbers. But there is a class
designed to handle these situations. Try this:

import java.text.DecimalFormat;
....
DecimalFormat formatter = new DecimalFormat( "#,##0" );
String s = "1,000";
int i = -1;
try {
i = formatter.parse( s ).intValue();
}
catch( ParseException e ) {
...
}

Don't you just love the javadocs?

 

[Roedy Green]

How to convert a string such as "1,000" to a number? I tried
Integer.parseInt("1,000");. But it did not work.

It does not like the comma. You will have to filter it out before
hand.

 

[Roedy Green]

DecimalFormat formatter = new DecimalFormat( "#,##0" );

When you do that, what sorts of string are acceptable. Does it insist
on the comma?

 

[Sudsy]

Roedy asks:

When you do that, what sorts of string are acceptable. Does it insist
on the comma?

It's actually very forgiving. It seems to completely ignore
the commas, the number of digits between them, etc. I wrote
this quick test:

public class NumberTest {
public static void main( String args[] ) {
DecimalFormat formatter = new DecimalFormat( "#,##0" );
int parsed;
String formatted;
for( int i = 0; i < args.length; i++ ) {
try {
parsed = formatter.parse( args
).intValue();
formatted = formatter.format( parsed );
System.out.println( "Original = " +
args +
", parsed = " + parsed +
", formatted = " + formatted );
}
catch( Exception e ) {
System.err.println( e.toString() );
}
}
}
}

Here's a test run:

$ java NumberTest 1,000 1000 4,1567,890 4567890 1,34546
Original = 1,000, parsed = 1000, formatted = 1,000
Original = 1000, parsed = 1000, formatted = 1,000
Original = 4,1567,890, parsed = 41567890, formatted = 41,567,890
Original = 4567890, parsed = 4567890, formatted = 4,567,890
Original = 1,34546, parsed = 134546, formatted = 134,546
$

So it's more powerful on the formatting end than the parsing one.
Fair enough!