How to check how many letters are in a string in java?

Question

How do you check how many letters are in a Java string?

How do you check what letter is in a certain position in the string (i.e, the second letter of the string)?

Is this homework? Have you tried looking at the Javadocs for the `String` class? — Cameron Skinner, Aug 31 '11 at 03:08
Did you read the Java API doc for `String`? It details the methods that tell you its length, as well as checking the character at a position. [link for the google challenged](http://download.oracle.com/javase/7/docs/api/java/lang/String.html) — wkl, Aug 31 '11 at 03:09
Possible duplicate of [Count letters in a string Java](http://stackoverflow.com/questions/19163876/count-letters-in-a-string-java) — Des Horsley, Oct 12 '15 at 05:20

score 48 · Accepted Answer · edited Nov 25 '13 at 05:11

48

A)

String str = "a string";
int length = str.length( ); // length == 8

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

edit

If you want to count the number of a specific type of characters in a String, then a simple method is to iterate through the String checking each index against your test case.

int charCount = 0;
char temp;

for( int i = 0; i < str.length( ); i++ )
{
    temp = str.charAt( i );

    if( temp.TestCase )
        charCount++;
}

where TestCase can be isLetter( ), isDigit( ), etc.

Or if you just want to count everything but spaces, then do a check in the if like temp != ' '

B)

String str = "a string";
char atPos0 = str.charAt( 0 ); // atPos0 == 'a'

http://download.oracle.com/javase/7/docs/api/java/lang/String.html#charAt%28int%29

edited Nov 25 '13 at 05:11

Afshin Moazami

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answered Aug 31 '11 at 03:10

ssell

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I think the number of letters is not necessarily equal to the string length - whitespace is not considered a letter, or is it? – emboss Aug 31 '11 at 03:12
I assumed he meant a simple string length. I'll edit with what your case – ssell Aug 31 '11 at 03:14
Sure, just wanted to make the question a bit more interesting ;) +1 anyway – emboss Aug 31 '11 at 03:16
Ok, new problem: my code editor, NetBeans, dosen't know the length() method. What should I do? – tussya Aug 31 '11 at 05:06
@tussya That is very odd... How are you using it? – ssell Aug 31 '11 at 05:30
int cleartextl=textaclr.length(); and for(int i=0;i>textaclr.length();i++){ – tussya Aug 31 '11 at 20:22
@tussya is `textaclr` a `String` object? There should be no reason why that does not work if it is. – ssell Sep 01 '11 at 04:29
Yeeeah, that was the problem. – tussya Sep 02 '11 at 05:57
3

If you are counting letters, the above solution will only work with ASCII characters. For example – ThomasMH Sep 20 '14 at 00:24
Does the space between the parenthesis in the above answer mean something? Or is `str.length( )` the same as `str.length()` ? – Moses Kirathe Aug 05 '18 at 00:25

score 7 · Answer 2 · answered Sep 20 '14 at 00:40

If you are counting letters, the above solution will fail for some unicode symbols. For example for these 5 characters sample.length() will return 6 instead of 5:

String sample = "\u760c\u0444\u03b3\u03b5\ud800\udf45"; // 瘌фγε

The codePointCount function was introduced in Java 1.5 and I understand gives better results for glyphs etc

sample.codePointCount(0, sample.length()) // returns 5

http://globalizer.wordpress.com/2007/01/16/utf-8-and-string-length-limitations/

score 5 · Answer 3 · answered Dec 20 '12 at 00:23

5

To answer your questions in a easy way:

    a) String.length();
    b) String.charAt(/* String index */);

answered Dec 20 '12 at 00:23

Alex Orzechowski

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String.length() returns the number of Unicode units, not the number of characters. The result will be correct only if every letter in a string is exactly 1 Unicode unit. – Andrei Volgin Nov 17 '16 at 19:35

score 0 · Answer 4 · answered Oct 12 '15 at 05:16

0

1) To answer your question:

  String s="Java";
  System.out.println(s.length());

answered Oct 12 '15 at 05:16

Anil Reddy

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score 0 · Answer 5 · answered Aug 19 '22 at 16:16

0

I could not get any of these answers to work for me using UTF-8. If you are using UTF-8, have a look at this post. I ended up using Guava's Utf8.

answered Aug 19 '22 at 16:16

SedJ601

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How to check how many letters are in a string in java?

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