how to take multiple input using NextLine() in java

Question

how to take more inputs from user using Nextline() in java if i use scn.Nextline() after reading one input it will work but giving a null in answer.

public class Mapdemo {

    public static void main(String[] args) {
        Scanner scn =new Scanner(System.in);
        System.out.println("enter the number of phoneaddress you want to store");
        int n=scn.nextInt();
        int j=0;
        System.out.println("enter the  phonenumber first and  then name of the person  phoneaddress");
        Map<String, Long> m1=new HashMap<String,Long>();
        for(int i=0;i<n;i++)
        {
            Long l=scn.nextLong();
            String s=scn.nextLine();
                m1.put(s,l);


        }

        System.out.println("enter the name to be checked");
        String s2=scn.next();
        System.out.println(m1.get(s2));

whatamidoingwithmylife · Answer 1 · 2017-12-01T17:52:16.933

1

After using .nextInt() for the first time do:

scanner.nextLine();

after that to clear the line, nextLine() stops at the newline character (OS dependant).

https://docs.oracle.com/javase/7/docs/api/java/util/Scanner.html#nextLine()

edited Dec 01 '17 at 17:52

answered Dec 01 '17 at 17:47

whatamidoingwithmylife

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Typo: I think you meant "After using .nextInt() for the first time" – BackSlash Dec 01 '17 at 17:49
no it will not work – wirelessbrain Dec 01 '17 at 17:49
@BackSlash yea, I didn't read his code thoroughly, just reacted based on a question. – whatamidoingwithmylife Dec 01 '17 at 17:51
@wirelessbrain just add this line: "scn.nextLine();" after "Long l=scn.nextLong();" – whatamidoingwithmylife Dec 01 '17 at 17:53
if we use scn.nextLine() after it takes input but while printing it is showing null.why?? – wirelessbrain Dec 01 '17 at 17:55
@wirelessbrain https://pastebin.com/gpLt76Xp – whatamidoingwithmylife Dec 01 '17 at 18:01
@wirelessbrain Here's a pic as well: https://ibb.co/gdMYVG – whatamidoingwithmylife Dec 01 '17 at 18:03
thanks for your effort.but try these test cases 7647464 mary lagan 5365533 smith will 665653 jhon – wirelessbrain Dec 01 '17 at 18:05
@wirelessbrain works fine: https://imgur.com/a/hTZjp Can you write here what exactly you want to do, do you want for someone to enter names and phone numbers and then print those numbers out, or print both names and numbers ? – whatamidoingwithmylife Dec 01 '17 at 18:11
user needs to put name and phone number and then by using key that is name he/she able to get the phone number .the name may contain space. – wirelessbrain Dec 01 '17 at 18:14
https://pastebin.com/GLAQWRVj that will print out names and numbers once you are finished entering them, to get the phone number by using name (key), you have to ask the use for the name they want to search for, then check if the map contains that name (key) and print it out if it does contain it, otherwise do something else like print "No such contact." – whatamidoingwithmylife Dec 01 '17 at 18:16
im facing this problem enter the number of phoneaddress you want to store 3 enter the phonenumber first and then name of the person phoneaddress 6736363 mary logan 565768734 ronald 764763 andy jhon enter the name to be checked andy jhon null – wirelessbrain Dec 01 '17 at 18:19
@wirelessbrain Try this code: https://pastebin.com/snVw6esC – whatamidoingwithmylife Dec 01 '17 at 18:32
Sure man, just don't give up, keep learning. – whatamidoingwithmylife Dec 01 '17 at 19:12

how to take multiple input using NextLine() in java

1 Answers1