Grabbing the integer out from a string...

[ganggang3ster]

Is there a method in String, Integer, or other classes that will
return the
integer within a string like:

int a = ClassName.method("I have 7 peanuts");
System.out.print(a);

Output:
7

I have an uneasy feeling that the answer may be no, and my current
solution uses regular expressions

Thanks!

 

[Lew]

     As far as I know, your uneasy feeling is justified.  I'd
probably use a regular expression, too, but I'd also worry about

        "I have 7,240 peanuts"
        "I have 7 240 peanuts"
        "I have 7.24 kilopeanuts"
        "I have seven peanuts"
        "I have VII peanuts"
        "I have 7 peanuts, 8 elephants, and a problem"

"The clip holds 10 9-mm rounds."

 

[Lew]

=A0 =A0 =A0As far as I know, your uneasy feeling is justified. =A0I'd
probably use a regular expression, too, but I'd also worry about

=A0 =A0 =A0 =A0 "I have 7,240 peanuts"
=A0 =A0 =A0 =A0 "I have 7 240 peanuts"
=A0 =A0 =A0 =A0 "I have 7.24 kilopeanuts"
=A0 =A0 =A0 =A0 "I have seven peanuts"
=A0 =A0 =A0 =A0 "I have VII peanuts"
=A0 =A0 =A0 =A0 "I have 7 peanuts, 8 elephants, and a problem"

"The clip holds 10 9-mm rounds."

--
Lew


- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
"I am not aware of any evidence showing that President Bush
or members of his administration have personally profited
from the attacks of 9-11"

--- Rep. Cynthia McKinney, D-Ga.

 

[Stefan Ram]

int a = ClassName.method("I have 7 peanuts");

public class Main
{
public static void main( final java.lang.String[] args )
{
final int a = new java.util.Scanner( "I have 7 peanuts" ).
skip( "[^\\d]+" ).nextInt();

java.lang.System.out.println( a ); }}

7

 

[Roedy Green]

Is there a method in String, Integer, or other classes that will
return the
integer within a string like:

hundreds of them. They are named like the French irregular verbs. I
wrote a program to generate you the correct code.

See http://mindprod.com/applet/converter.html

 

[Lew]

int a = ClassName.method("I have 7 peanuts");

public class Main
{
  public static void main( final java.lang.String[] args )
  {
    final int a = new java.util.Scanner( "I have 7 peanuts" ).
    skip( "[^\\d]+" ).nextInt();

    java.lang.System.out.println( a ); }}

7

"I flew on the 1,000th 747 and an F-16 200 times for under 100 Euros
by calling +011 14 987662 1,000 times on 2006-06-06 and answering the
sixth question, 'What is 222 times 3?'"

How does one know to pick up "1,000" as the int "1000"? That "747"
does not actually represent an int but a word? That "16" is not
separate but part of "F-16"? That "2006-06-06" represents a date, not
an int? That "sixth" does represent an int? That "222 times 3"
really represents a single int?

 

[puzzlecracker]

    skip( "[^\\d]+" ).nextInt();

Would you explain the regular expression, not sure what it means?
thanks

 

[Stefan Ram]

skip( "[^\\d]+" ).nextInt();

Would you explain the regular expression, not sure what it means?

"[^\\d]+" is a Java string literal.

The regular expression is the value of that literal, i.e.,

[^\d]+

. This can be simplified to

\D+

. (I was still young and inexperienced when I wrote "[^\\d]+".)

»\D« and »+« each can be looked up in the following pages.

http://download.java.net/jdk7/docs/api/java/util/regex/Pattern.html

 

[Danger_Duck]

Is there a method in String, Integer, or other classes that will
return the
integer within a string like:

int a = ClassName.method("I have 7 peanuts");
System.out.print(a);

Output:
7

I have an uneasy feeling that the answer may be no, and my current
solution uses regular expressions

Thanks!

Thanks guys.

And Lew, obviously I'm not applying this to everything-I have output
from code that always comes in a predictable form like "function f1
occurred 5 times 100% of blocks executed"

So, as I read line by line of basically the same thing over and over
again (with the two numbers and function name changing), I naturally
wanted to know if there was an easy way to pick out the integers or
split it up at the first int if 2 or more numbers in a string would
make things confusing.

By the way Stefan, is it possible to use regular expressions to do
something like line.substring(line.indexOf(FIRST NUMERICAL VALUE)) ?

Again, often times I may want to split up strings that occur regularly
like the one above but don't care particularly for the exact number,
though I know the pattern is always the same.

Thanks again!

 

[Andrew Thompson]

So, as I read line by line of basically the same thing over and over
again (with the two numbers and function name changing), I naturally
wanted to know if there was an easy way to pick out the integers or
split it up at the first int if 2 or more numbers in a string would
make things confusing.

<sscce>
class FirstInt {
public static void main(String[] args) {
String s = args[0];
String[] parts = s.split(" ");
for (int ii=0; ii<parts.length; ii++) {
try {
Integer i = new Integer(parts[ii]);
System.out.println(i);
break;
} catch(Exception e) {
// continue
}
}
}
}
</sscce>

[IP]
java FirstInt
java FirstInt "I have 7 peanuts"
java FirstInt "I have 21 peanuts in 3 pockets"
[/IP]

[OP]
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 0
at FirstInt.main(FirstInt.java:3)
7
21
[/OP]

 

[Jussi Piitulainen]

from code that always comes in a predictable form like "function f1
occurred 5 times 100% of blocks executed"

So, as I read line by line of basically the same thing over and over
again (with the two numbers and function name changing), I naturally
wanted to know if there was an easy way to pick out the integers or
split it up at the first int if 2 or more numbers in a string would
make things confusing.

import java.util.regex.Pattern;
import java.util.regex.Matcher;
class M {
public static void main(String [] args) {
Pattern p
= Pattern.compile("function (\\w+)"
+ " occurred (\\d+) times"
+ " (\\d+)% of blocks executed");
for (int k = 0 ; k < args.length ; ++ k) {
Matcher m = p.matcher(args[k]);
if (m.matches()) {
System.out.println("group 1 == |" + m.group(1) + "|");
System.out.println("group 2 == |" + m.group(2) + "|");
System.out.println("group 3 == |" + m.group(3) + "|");
}
}
}
}

$ java -cp . M "function foo03_1 occurred 704 times 39% of blocks executed"
group 1 == |foo03_1|
group 2 == |704|
group 3 == |39|

 

[Tom Anderson]

"The clip holds 10 9-mm rounds."

"I am l33t."

Anyway, it's time for my favourite Jamie Zawinski quote:

"Some people, when confronted with a problem, think 'I know, Ill use
regular expressions'. Now they have two problems."

tom