How to multiply the number of a string by a number

Question

I am currently programming a progress bar in Java. I would like to add only every 10% the character # . What is the best way to do this? I would like every 1% the value output. I tried something once. However, it does not quite work. There is an error at loader * (number / number), number) . I don't want to write this under each other, but all in one line.

How can I improve it?

String laoder = "#";
int rounds = 1000; // Could be 10000, 250000, 60000, ... 
// This is 1% 
int number = 1000 / 100;
for(int i=0; i < 1000; i++){
    // This is X % 
    if(i == number) {
        // I want to print the # every 10 % and the normale percentage every 1% 
        // For example 
        // [#         ] 1%
        // [#         ] 2%
        // ....
        // [##        ] 10%
        // [##########] Done
        System.out.printf("[# %s                    ] \r \s%", loader * (number / number), number);
        // This work, but how can I combine both
        System.out.print(repeat(laoder , number / 10) + " \r");
        number += number;
    }

    Thread.Sleep(500)
}
public static String repeat(int count, String with) {
    return new String(new char[count]).replace("\0", with);
}

Answer 1

It's a fun problem to solve indeed. Below is one way of doing it. All calculation is done using integer numbers (no floating point).

Just note that the total must be greater than 0.

Have fun!

int total = 100; // must be greater than 0
char[] progressBar = new char[10];
Arrays.fill(progressBar, ' ');
for (int progress = 0; progress <= total; progress++) {
    int percentage = progress * 100 / total;
    Arrays.fill(progressBar, 0, percentage / 10, '#');
    System.out.println("[" + String.valueOf(progressBar) + "] " + percentage + "%");
}

Sample output:

[          ] 0%
[#         ] 10%
[##        ] 20%
[###       ] 30%
[####      ] 40%
[#####     ] 50%
[######    ] 60%
[#######   ] 70%
[########  ] 80%
[######### ] 90%
[##########] 100%

Answer 2

First off as @sanjeevRm suggested the condition on the iff will be evaluated only on the first 10% so you'd have to change it to

if(i%number==0) {
  ...
}

For the string part I'd suggest to build the string first and then print it to ease the manipulation of it

public String loadString(int hashCount, int maxHashCount) {
    String loadString = "[";
    //fill in the current loading percentage
    for(int i=0; i<hashCount; i++)
        loadString+="#";

    //now fill in the remaining with white spaces
    for(int k=0; k<(maxHashCount-hashCount); k++)
        loadString+=" ";

    loadString += "]";
    return loadString;
}

Now within the original for loop just call the method using

loadString(i/number, rounds/number);

SN: I'm not sure this is a fix to make but you wrote that number is 1% that doesn't seem right as you're actually dividing it by 10 and not by 100. Also to make it more dynamic you should initialise the number as

number = rounds/10; //number is the 10% of the rounds keep in mind

Answer 3

This shows one way of coding it. You may want to tweak the rounding bits to your taste.

public class TestProgress {
    
    private static String getProgress(int current, int total) {
        float status = (float)current/(float)total*100;
        
        String bar = "";
        while(bar.length()*10 < status) {
            bar += "#";
        }
        while(bar.length()<10) {
            bar += " ";
        }
                
        return String.format("%3.0f [%s]", status, bar);
    }

    public static void main(String[] args) {
        for (int i=0;i<5000;i++) {
            System.out.print(getProgress(i, 5000));
            System.out.print("\r");
        }
    }
}

Answer 4

Try this.

System.out.printf("\r[%-10s] %d%%", repeat(percent / 10, "#"), percent);

Answer 5

The way to print over the same line in the console is to print the carriage return character. In java code this is done using the following code.

System.out.print("\r");

This simply returns the cursor to the start of the line.

The below code implements your requirements.

• It always prints on the same line.
• It prints the progress bar correctly.
• It prints the percent completed after the progress bar.
• It prints Done when the progress reaches 100 percent.

int rounds = 1000;
int onePercent = rounds / 100;
int tenPercent = rounds / 10;
int count = 0;
String progress;
for (int i = 1; i <= rounds; i++) {
    if (i % onePercent == 0) {
        if (i >= onePercent) {
            System.out.print("\r");
        }
        progress = "[";
        if (i % tenPercent == 0) {
            count++;
        }
        for (int j = 0; j < count; j++) {
            progress += "#";
        }
        for (int k = count; k < 10; k++) {
            progress += " ";
        }
        progress += "] ";
        if (count == 10) {
            progress += "Done";
        }
        else {
            progress += (i / onePercent) + "%";
        }
        System.out.print(progress);
        try {
            Thread.sleep(500);
        }
        catch (InterruptedException x) {
            // Ignore.
        }
    }
}
System.out.println();