Format text with a list of argument in java

I have a sting with multiple %s for string formatting. And i have an array of strings which are supposed to be arguments for string formatting. Like this

List<String> list = new ArrayList<>();
list.add("A");
list.add("B");
String toFormat =  "This is a first value %s, This is a second value %s"
String result = String.formant (toFormat, list.get(0), list.get(1));

But it doesn't look good with a number of element greater than 2. How can i format a string without picking each argument from list individually?

String.format() take as parameters a format and array of Objects (vararg is an array of Objects behind the scene). All you need to do is to convert your list to array of Strings and pass that to String.format(), like so:

public static void main(String args[]) {
    List<String> list = new ArrayList<>();
    list.add("A");
    list.add("B");
    String toFormat =  "This is a first value %s, This is a second value %s";
    String result = String.format (toFormat, list.toArray(new String[0]));
    System.out.println(result);
}

Rethink your question:

String toFormat =  "This is a first value %s, This is a second value %s"

So the point is: you have multiple arguments, but each argument should be treated specially. Meaning: assume you have 3 arguments. Then your format must include this is the third value. And when you have 4 arguments, the string fourth ... must come from somewhere!

If that is what you want, then you need an additional mapping, like:

Map<Integer, String> namedPositionByIndex = ...

that maps pairs like (1, "first"), (2, "second") and so on.

And using that map, you can now pull together a string that works dynamically. Of course, it will only work for the largest index in your map.

Can you use the String Builder and use it to build a big string dynamically.

With Java8 or greater, you can do something like this

import java.util.List;
import java.util.ArrayList;
import java.lang.StringBuilder;

class Main {
  public static void main(String[] args) {
    List<String> list = new ArrayList<>();
    list.add("A");
    list.add("B");
    StringBuilder builder = new StringBuilder();
    list.forEach(it -> {
        builder.append(String.format("This is a first value %s,", it)
      }
    ));
    System.out.print(builder.toString());
  }
}

The result looks like: This is a first value A,This is a first value B,

You can add more code inside the forEach to fix the string patter