CODEWITHSUNDEEP
java
mee
mee

Reputation: 851

compare two numeric String values

I have a simple doubt. Would be great if anyone helps me.

I have two strings: 

String string1 = "4"; // and 
String string2 = "04";

Both the values are equal but how to compare them in java? We have equals and equalsIgnoreCase for comparing String alpha values, similarly how to compare numeric values.

Upvotes: 19

Views: 135812

Answers (7)

Animesh Nag
Animesh Nag

Reputation: 11

if(String.valueOf(S1).compareTo(String.valueOf(S2)) < 0)

Upvotes: 0

yakob abada
yakob abada

Reputation: 1297

The comparison happens on chacracter basis. so '2' > '12' is true because the comparison will happen as '2' > '1' and in alphabetical way '2' is always greater than '1' as unicode. SO it will comeout true.

Upvotes: 1

Viktor Mellgren
Viktor Mellgren

Reputation: 4506

Skipping parsing it to an int at all to handle arbitrarily large numbers, only comparing the strings. As a bonus it also works for decimal numbers (unless there are trailing zeroes, where you probably can do similar thing with anchoring end of string instead).

You can omitt the trim if you are sure there are no whitespace characters

    String string1 = "4"; // and
    String string2 = "04";

    String noLeadingZeroes1 = string1.trim().replaceFirst("^0+(?!$)", "");
    String noLeadingZeroes2 = string2.trim().replaceFirst("^0+(?!$)", "");

    System.out.println(noLeadingZeroes1.equals(noLeadingZeroes2));

Upvotes: 4

Jin Kwon
Jin Kwon

Reputation: 22025

Don't forget the BigInteger for very long values.

return new BigInteger(s1).compareTo(new BigInteger(s2));

Upvotes: 17

Colin D
Colin D

Reputation: 5661

Use the Integer class to convert the strings to integers.

http://docs.oracle.com/javase/7/docs/api/java/lang/Integer.html#parseInt%28java.lang.String%29

Integer.parseInt(string1) == Integer.parseInt(string2)

Upvotes: 3

Rohit Jain
Rohit Jain

Reputation: 213401

Integer.parseInt("4") == Integer.parseInt("04")

That is it. You can convert a numeric string into integer using Integer.parseInt(String) method, which returns an int type. And then comparison is same as 4 == 4.

Upvotes: 24

Deepak Bala
Deepak Bala

Reputation: 11185

Integer.valueOf(string1).equals(Integer.valueOf(string2));

Upvotes: 9

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