How to take input as String given the String Length

Question

How to take input from User as String given the String Length

The problem link:

http://www.practice.geeksforgeeks.org/problem-page.php?pid=295

MyApproach:

I used Scanner for the task to take the number of testcases and then took the String length as input:

But I am confused how to take String of specified length.My search found that there is no method or constructor which can take string of specified length.

Can Anyone guide?

Below is my code:

 Scanner sc=new Scanner(System.in);
 int T=sc.nextInt();
 for(int i=1;i<=T;i++)
  {
    int Strlength=sc.nextInt();
    String strnew=sc.next(); //How to take Stringofspecified character
    ..........
     .........
   }

you would want to read every char separately or read the whole line (nextLine()) and then just use the first n characters. — redxef
– redxef, Commented Jan 19, 2016 at 14:00

birkett · Accepted Answer · 2016-01-19 14:05:42Z

2

You can't do that, you can simply force the user to reinsert the String if the length of the String does not match the given input.

 Scanner sc=new Scanner(System.in);
 int T=sc.nextInt();
 for(int i=1;i<=T;i++)
  {
    int Strlength=sc.nextInt();
    String strnew = null;
    while (strnew == null || strnew.size() != Strlength) {
      strnew = sc.next(); 
    }
    ..........
     .........
   }

edited Jan 19, 2016 at 14:05

answered Jan 19, 2016 at 14:00

birkett

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2 Comments

Jason arora Over a year ago

Zandanra Okay.Shouldn't the strnew.size()== Strlength) be equal?Then only we can take the input from user.

birkett Over a year ago

If you write strnew.size() == Strlength, you will execute the block of while each time the user insert a String of correct size. That is not what you want, you want to continue asking for user input until the input is correct. Once the user has inserted a String of length Strlength (strnew.size() == Strlength), the while loop will not execute anymore and you can perform your calculations

ctst · Accepted Answer · 2016-01-19 14:14:42Z

1

A way to do this is inserting some kind of test, e.g.:

String strnew;
do{
   strnew=sc.next(); //How to take Stringofspecified character
}
while(strnew.length() != Strlength);

edited Jan 19, 2016 at 14:14

answered Jan 19, 2016 at 14:07

ctst

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1 Comment

ctst Over a year ago

we could merge this answer with Simone Zandara's answer (since he was faster), since they mostly do the same. do-while just saves us the null-check.

Tom Taylor · Accepted Answer · 2019-06-11 20:44:03Z

1

    String S = "";
    Scanner sc = new Scanner(System.in);
    int D = sc.nextInt();
    for(int i=0;i<D;i++) {
         S = S + sc.next();
    }
    System.out.println(S);

edited Jun 11, 2019 at 20:44

Tom Taylor

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answered Jun 11, 2019 at 17:33

vibhaw geass

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1 Comment

vibhaw geass Over a year ago

makes string of specific length

Pang · Accepted Answer · 2018-08-22 07:23:12Z

0

I figured out a way to do this.

Scanner sc = new Scanner(System.in);
int strLength = sc.nextInt();
sc.nextLine(); 
String strInput = sc.nextLine();
if(strInput.length()>strLength)
{
    str = str.substring(0, strlength);
}
// Now str length is equal to the desired string length

edited Aug 22, 2018 at 7:23

Pang

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answered Aug 22, 2018 at 7:21

User9211

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