text.compareTo() what does this means?

Question

String ntext;
ntext = something;
String currentLine;
currentLine = something;

while(ntext.compareTo(currentLine) != 0){
    //some condition
     }

Here i want to know what that compareto actually do. One more questin what we can use to compare two objects?

It does what it says on tin. What are the types of `ntext` and `currentLine`? — Boris the Spider, Apr 24 '16 at 16:36
There is documentation that you can read.... https://docs.oracle.com/javase/8/docs/api/java/lang/String.html#compareTo-java.lang.String- if this is a String, or the general https://docs.oracle.com/javase/8/docs/api/java/lang/Comparable.html#compareTo-T- — Tunaki, Apr 24 '16 at 16:36
@Tunaki can you think of any reason why `equals` wouldn't work? Something related to larger character sets for example? — Boris the Spider, Apr 24 '16 at 16:37
That could be written as `while (!ntext.equals(currentLine)) {` - does that make its meaning more clear? — Andy Turner, Apr 24 '16 at 16:38
@BoristheSpider Nope. Well except if the class is broken to begin with and doesn't have consistent `equals` and `compareTo` :). (it is *strongly recommended, but not strictly required*...) — Tunaki, Apr 24 '16 at 16:39

score 0 · Accepted Answer · answered Apr 24 '16 at 16:37

If those variables are strings (i assume so) it checks if they are equal, returns 0 if so, and another number if not. See the JavaDoc here: http://docs.oracle.com/javase/7/docs/api/java/lang/String.html#compareTo%28java.lang.String%29

More specifically, it goes through both strings character by character. When it finds a string of one that is not equal to the other, it returns a number representing whether the differing character is more than, less than, or equal to the corresponding character in the other string.

text.compareTo() what does this means?

1 Answers1