Printing initials of user input name of any length along with full surname in java

Question

I am new to java and I have been trying to solve a problem which I feel might have a simpler answer than my code.The problem was to print the initials of a user input name of any length along with the full surname.But this has to be done without any String.split() or arrays.I tried getting the user to input his name one word at a time, but is there any there a possible way to get the whole name at once and do as required. My code is as follows:

import java.io.*;
public class Initials {
    public static void main(String[]args)throws IOException{
        BufferedReader br =  new BufferedReader(new InputStreamReader(System.in));
        System.out.println("Enter the number of words your name contains");
        int n=Integer.parseInt(br.readLine());
        String str="";
        for(int x=1;x<=n-1;x++){
            System.out.println("Enter your name's word number:"+" "+x);
            String s=br.readLine();
            String st=s.toUpperCase();
            char ch=st.charAt(0);
            str=str+ch+".";
        }
        System.out.println("Enter your surname");
        String sur=br.readLine();
        str=str+" "+sur.toUpperCase();
        System.out.println(str);
    }
}

Did you try getting the whole name at once? How did you approach working with that? — Rohit Jain, Jun 26 '13 at 14:45
I inputted the name word by word,initializing it in uppercase.Then I just added the last word of the name to the already initialized string. — Abhinav, Jun 26 '13 at 14:49
Yeah but it didn't work out.I can't use arrays or String.split().I wouldn't be asking this if i did. — Abhinav, Jun 26 '13 at 14:53

arshajii · Answer 1 · 2013-06-26T15:05:04.893

Use a regular expression (namely (?<=\w)\w+(?=\s)):

String name = "John Paul Jones";  // read this from the user
System.out.println(name.replaceAll("(?<=\\w)\\w+(?=\\s)", "."));

J. P. Jones

No split(), no arrays :)

A little explanation: We essentially want to replace all letters of each word that is followed by a whitespace character except the first letter, with a . character. To match such words, we use (?<=\w)\w+(?=\s):

(?<=\w) is a positive lookbehind; it checks that a word-character exists at the start of the match but does not include it in the match itself. We have this component because we don't want to match the first character of each name, but rather all but the first (except for the last name, which we'll deal with shortly).
\w+ matches any continuous string of word characters; we use this to match the rest of the name.
(?=\s) is a positive lookahead; it checks that our match is followed by a whitespace character, but does not include it in the match itself. We include this component because we don't want to replace anything on the last name, which should not be followed by a whitespace character and hence should not match the regular expression.

You should also explain what does this regex do, if the OP doesn't know regex or how regexes work he won't understand what you coded — BackSlash, Jun 26 '13 at 14:58

Tani.c · Answer 2 · 2016-06-23T09:23:17.347

Another way around---

import java.util.Scanner;
  //a class that will print your output
class Initial {
  public void Initials() {
    Scanner sc = new Scanner(System.in);
    System.out.print("Enter Full name:");
    String name = sc.nextLine();
    int l = name.length();
    int pos = 0;
    for (int i = l - 1; i >= 0; i--) {
      char ch = name.charAt(i);
      if (ch == ' ') {
        pos = i; //getting the last space before Surname
        break;
      }
    }
    System.out.print("The initials are: ");
    System.out.print(name.charAt(0) + ".");//prints first name initial 
                                              //   with dot
    for (int x = 1; x < pos; x++) //finds midname initial
    {
      char ch = name.charAt(x);
      if (ch == ' ') {

        System.out.print(name.charAt(x + 1) + ".");
      }
    }
    for (int i = pos; i < l; i++) { //for printing Surname
      System.out.print(name.charAt(i));
    }

  }
}

public class Str {
  public static void main(String[] args) {
    Initial i = new Initial();
    i.Initials();
  }
}

score -1 · Answer 3 · edited Aug 01 '18 at 19:44

//This code will work for any no. of words in the name

class Surnam { 
    public static void main(String name) { 
        name = " " + name;
        int l=name.length(), p=0, m=0, r=0;
        char y;
        String word=" ", words=" ";
        for(int i = 0; i = 0; i--) {
            y=name.charAt(i);
            if(y==' ') { 
                r=name.lastIndexOf(y); //extracting the last space of the string
                word=name.substring(i,l); //extracting the surname
                words=name.replace(word," "); //removing the surname break;
            }
        }
        for (int i = 0; i <= r - 1; i++) {
            char x=words.charAt(i);
            if (x == ' ') {
                System.out.print(words.charAt(i + 1) + "."); //Printing all initials before the surname with a dot
            }
        }
        for (int i = l - 1; i >= 0; i--) {
            char x=name.charAt(i);
            if(x==' ') {
                m=i;
                name=name.substring(m,l); //extracting the surname
                name=name.trim(); //removing all the spaces before the surname
                System.out.print(name);
                break;
            }
        }
    }
}

Printing initials of user input name of any length along with full surname in java

3 Answers3