need help

Question about the task

Long words

Java Core, Level 9, Lesson 11

Resolved

How can i remove the last element without using StringBuilder data

while(br.ready){
String s = br.readLine();
String[] str = s.split(" ");
for(String s1 : str){
if(s1,length()>6){
bw.write(s1+",");
}
}
}

it almost does the same thing but can't delete the last element.

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Ian De Bie Full Stack Developer

21 October 2020, 22:43

another option is just using String.join

public static void main(String[] args) throws IOException {
    List<String> lines = new ArrayList<>();
    try (BufferedReader input = new BufferedReader(new FileReader(args[0]));
         FileWriter output = new FileWriter(args[1])) {
        while (input.ready()) {
            String[] line = input.readLine().split("\\s+");
            String[] arr = Arrays.stream(line).filter(f -> f.length() > 6).toArray(String[]::new);
            lines.addAll(Arrays.asList(arr));
        }
        output.write(String.join(",", lines));
    }
}

Nouser

Level 36 , Germany

31 August 2020, 06:28

useful

a regular loop with an if clause would do, but why not use StringBuilder?

while(br.ready()){
    String s = br.readLine();
    String[] str = s.split(" ");

    for (int i = 0; i < str.length; i++) {
        if (str.length > 6) {
            if (i < str.length - 1)
                bw.write(str[i] + ", ");
            else
                bw.write(str[i]);
        }
    }
}

or instead if the inner if-else

if (i > 0)
    bw.write(", ");
bw.write(str[i]);

dhanush

Level 30 , Chennai, India

31 August 2020, 08:50

Actually i completed the task using StringBuilder but before come to an idea of Stringbuilder i simply just used the String data type and try to remove the last element after printing the words it doesn't make sense so i changed my mind and completed using Stringbuilder. Now i just wanted to know that using String data type how can i possibly delete the last character may be without the help of Stringbuilder it cannot be possible because String data type is immutable. I tried your code it doesn't delete the character. :(

Nouser

Level 36 , Germany

31 August 2020, 09:33

solution

The second solution will work alone (without outer if condition). So it needs to be adapted to work in this example. The first example works, however the outer if condition is errornous. Should read for (int i = 0; i < str.length; i++) { So this works for me...

String fileNameIn = args[0];
String fileNameOut = args[1];

try (BufferedReader in = new BufferedReader(new FileReader(fileNameIn));
     BufferedWriter out = new BufferedWriter(new FileWriter(fileNameOut))) {

    while(in.ready()){
        String[] str = in.readLine().split(" ");

        for (int i = 0; i < str.length; i++) {
            if (str[i].length() > 6) {
                if (i < str.length - 1)
                    out.write(str[i] + ",");
                else
                    out.write(str[i]);
            }
        }
    }
} catch (IOException e) {
    e.printStackTrace();
}

Nouser

Level 36 , Germany

31 August 2020, 09:47

or use substring

String result = "";
while(in.ready()){
    String[] str = in.readLine().split(" ");
    for (String parts : str) {
        if (parts.length() > 6) {
            result += parts + ",";
        }
    }
}
out.write(result.substring(0, result.length()-1));

dhanush

Level 30 , Chennai, India

31 August 2020, 10:25

I already tried using subString it doesn't print anything to the writer file but by using if clause it does the work but doesn't verify the task donno why, and without the try with resource it also doesn't print anything. It's Better to use StringBuilder i think so,may be this task is insist to use the StringBuilder class. Thank you for your help!