A little confused about charAt()

[beijct]

Hi all, I'm trying to use the charAt() method to, obviously, reference a character by its index in a string; however, I'm a little confused about the paramaters it takes. Docs.oracle says the only parameter it takes is an index but that seems wrong, which string exactly am I looking at when using charAt() and how would I specify which string I want it to look at?

[wsaryada]

Why do you think the documentation is wrong? The charAt() method of the java.lang.String class is only need a single method which is the index of the character in the string that you want to read. And the parameter type is an integer. Here is an example how to use it:

String str = "The quick brown fox jumps over the lazy dog.";

char c = str.charAt(10);
System.out.println("c = " + c);

This code will give you the letter "b" which is the character at index number 10. String index start from 0.

[JosAH]

Hi all, I'm trying to use the charAt() method to, obviously, reference a character by its index in a string; however, I'm a little confused about the paramaters it takes. Docs.oracle says the only parameter it takes is an index but that seems wrong, which string exactly am I looking at when using charAt() and how would I specify which string I want it to look at?

I can understand your confusion; from a pure procedural point of view a charAt( ... ) method would need two parameters: a String and and int index; in an object oriented world methods have one implicit parameter: the object on which you call the method; in old versions of C++ there always was a first explicit parameter named 'this'; it was a pointer to this additional parameter. We don't need to program like that anymore, i.e. the compiler takes care of it all; e.g. when we write "foo".charAt(0) the compiler translates it for us to charAt("foo", 0) (and there's your second parameter again)

kind regards,

Jos