Issue with Read Character by Character of a String : JAVA

Question

I have a very long String and I want to read character by character until the end of the String.

In Java, I found two ways to read it:

Using CharAt.
Using StringReader.

Can anybody help me:

Which one is the faster way ?
How to use StringReader to read character by character until the end of the String ?

Thanks in advance.

score 3 · Accepted Answer · answered Mar 21 '12 at 17:32

3

Measure it and find out! Seriously, things may be different for me on my hardware compared to you on your hardware. But I suspect charAt()
It's just a Reader, so it has the same methods as any other Reader, including int read() which will return you the Unicode code point for each character, one by one

answered Mar 21 '12 at 17:32

dty

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Thanks. But why you suspect ? Is there any specific reason ? – Arpssss Mar 21 '12 at 17:47

score 2 · Answer 2 · answered Mar 21 '12 at 17:33

2

Measure it yourself. I can't see there being a meaningful/significant difference, once the string is loaded into memory.
StringReader#read() (RFTD)

answered Mar 21 '12 at 17:33

Matt Ball

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score 2 · Answer 3 · answered Mar 21 '12 at 17:33

2

How long is "very long?"

Convert the string to a char array using the toCharArray() method and have at it from a loop:

String mystring = "test";

char[] myCharArray = mystring.toCharArray();

answered Mar 21 '12 at 17:33

That doesn't answer either question the OP asked. – Matt Ball Mar 21 '12 at 17:34
1

He wants to "read character by character until the end of the string." – Mar 21 '12 at 17:36
And then he says that in Java he found two ways to read it and I am offering him a third way that might work. – Mar 21 '12 at 17:58
In case you need more convincing that I'm not trolling: http://stackoverflow.com/questions/1672415/charat-or-substring-which-is-faster – Mar 21 '12 at 18:44

score 1 · Answer 4 · answered Mar 21 '12 at 18:18

Here is a simple class designed to do as you requested, with a charAt method:

public class Test {

static String tS = "Hello this is a string";


public static void main (String args []) {
//make a blank character that gets replaced each time the for loop runs     
char c;     
    for (int j = 0; j < tS.length(); j++) {
            //for loop runs up the length of the string, then sets c to the
            //current character in the string. Printing c just proves the concept.
        c = tS.charAt(j);
        System.out.println(c);
    }
}
}

Please remember that none of this needs to be done in a class or a main method - you could do it anywhere within your code that you needed it.

Issue with Read Character by Character of a String : JAVA

4 Answers4