how to find the number of characters in a string

[s john smith]

how to find the number of characters in a string without using standard library functions?

[Rob Spoor]

You don't. This is probably some interview question to make you think outside the box, but the answer is simple - it's not possible. The obvious choice, String.length(), is not allowed. Another approach is to get the length of the backing char[], but that requires a call to toCharArray() - not allowed. Yet another approach is to get the next character until you encounter an IndexOutOfBoundsException (which you catch), but guess what - getting the character requires charAt(index) which is also not allowed.

If you use our search you'll find a few more threads with the same question, and the answer is going to be the same.

I found one such thread, but that only disallowed using length(). You're not allowed to use anything.

[fred rosenberger]

I was gonna say print it to the screen and count, but even that requires a System.out.println() call, which is - you guessed it - not allowed.

[Jeff Verdegan]

Please UseOneThreadPerQuestion.(⇐click)

[Matthew Brown]

Sounds to me like a question about C that's been translated to Java without realising it doesn't make sense in Java. In C you've got pointer arithmetic and null-terminated strings, and this would be a reasonable question.

[Rod Singh]

In c language, you can write a function to calculate length of a string, and let your java program call it using JNI.

[fred rosenberger]

Rod Singh wrote: In c language, you can write a function to calculate length of a string, and let your java program call it using JNI.

wouldn't using the JNI require you to use "standard library functions"?

[Rob Spoor]

I'd say so.