it is possible to fix this? setCharAt is red.

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Hello, I went down the string cutting way. so I have an array filled with words. I found an example on the internet and tried to modify it, but it didn't work out. There is some collision between String and Char. I also found a conclusion about setCharAt, I tried but I don't know how to apply it. "( setCharAt in defined for StringBuilder or StringBuffer not on String. to change a char on string you have to covert it to either char array of a String buffer or builder. Char array is a decent approach for you as you are playing with each and every character. Go with the StringBuilder or StringBuffer approach, which will be easy to code, and the readability of the code also will be good. Use whichever you are comfortable with. )". I also saw one pretty simple solution on the help forum under my thread, it was from the archived thread. And I wonder whether to abandon my idea and make this simple uncomplicated solution.

package pl.codegym.task.task08.task0823; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.util.ArrayList; import java.util.HashSet; import java.util.Set; /* Ruszamy na cały kraj */ public class Solution { public static void main(String[] args) throws IOException { BufferedReader reader = new BufferedReader(new InputStreamReader(System.in)); String s = reader.readLine(); //tutaj wpisz swój kod String[] arrayParts = s.split(" "); for (String testPrint : arrayParts) // test print array System.out.println(testPrint); //String[] newArrayParts = new String[10]; //StringBuffer arrayParts = new StringBuffer(s1); //String arrayParts = s1.toString(); //String newArrayParts = forarrayparts.toString(); for (String s1 : arrayParts) { if (Character.isLowerCase(s1.charAt(0))) { //Convert it into upper case using toUpperCase() function arrayParts.setCharAt(0, Character.toUpperCase(s1.charAt(0))); // setCharAt why is red? } } for (String testPrint : arrayParts) { // test print new array System.out.println(testPrint); } for (String testPrint : arrayParts) { // final print System.out.print(testPrint); System.out.print(" "); } } }

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Lisa

Poziom 41

27 lipca 2021, 12:04

You have two problems... or maybe three ;) 1. you try to invoke setCharAt on a String array... you probably meant s1 2. still that won't work as setCharAt is a StringBuilder method. Just compare to the text of the solution you found: 'setCharAt in defined for StringBuilder or StringBuffer not on String' So you need to create a StringBuilder object, call setCharAt on that sb object and convert it back to a String... no biggie

StringBuilder sb = new StringBuilder(s1);
sb.setCharAt(0, Character.toUpperCase(sb.charAt(0)));
// save that in the array, another array or collection: sb.toString();

3. If you did that, you still won't get your desired result. Each of these array parts are saved in a string, the first letter capitalized and then thrown away. You haven't saved the result back into the array. That points still to the original string. So you need to use a numbered loop so you can access each array element and set those. You already have seen other solutions and I'd like to show you another very cheap one... you can do it either with string methods or you can convert the string to a char array. That's what I do here. Then I uppercase the first element (maybe you need to add a check if the array length is > 0 if the validator complains) and then I just uppercase the each char after a space. The loop is to < length -1 so we do not run into an ArrayIndexOutOfBoundsException

char[] ch = s.toCharArray();
System.out.print(Character.toUpperCase(ch[0]));
for (int i = 0; i < ch.length - 1; i++)
    System.out.print(ch[i] == ' ' ? Character.toUpperCase(ch[i + 1]) : ch[i + 1]);

Lisa

Poziom 41

27 lipca 2021, 12:10

rozwiązanie

And you can use String.toUppercase together with String.substring to build together a resulting string where the first char is capitalized.

String s = "test";
String result = s.substring(0,1).toUpperCase(); // first char capitalized and saved in result
result += s.substring(1); // concatenating the rest
System.out.println(result);

Robert

Poziom 17 , Debica, Poland

27 lipca 2021, 14:10

I follow that lead. Is pretty cool this .substring() I did that this way:

if (!arrayParts[i].isEmpty()) {
arrayParts[i] = arrayParts[i].substring(0, 1).toUpperCase() + arrayParts[i].substring(1).toLowerCase();
}

Now i have output: Ja Janek. There was a problem with spaces, i didn't want space to after last word. And i print it that way:

for (int i = 0; i < arrayParts.length; i++) {
            System.out.print(arrayParts[i]);
            if ( i != arrayParts.length-1) {
                System.out.print(" ");
            }
}

The inner if, places spaces between words, but not after the last word.

Robert

Poziom 17 , Debica, Poland

27 lipca 2021, 14:16

In the end, it was not a way out of this archived thread. Thank You. :)

Lisa

Poziom 41

27 lipca 2021, 16:54

my pleasure ;) and that's a very good solution you have coded. And just to show you that it is possible to do with StringBuilder, too

String[] arrayParts = s.split("\\s+");
for (int i = 0; i < arrayParts.length; i++) {
    StringBuilder sb = new StringBuilder(arrayParts[i]);
    sb.setCharAt(0, Character.toUpperCase(sb.charAt(0)));
    System.out.print((i == 0 ? "" : " " ) + sb);
}