java - How do I fix my scanner input that is null? -


hi new @ java programming , ran problem on latest project. making score generator bowling , finished code, except when went test it, said

"exception in thread "main" java.lang.nullpointerexception @ bowling_score.main(bowling_score.java:34)"

i tried fix it, , looked through tons of websites, no solutions solved problem. it's easy fix, can't seem find answer. line has problem second line here.

    system.out.println("frame 1, throw 1");     frame1throw1 = sc.nextint();

this way know how use scanner variables, if there better way please tell me. may problem because variable frame1throw1 first variable on list.

the variable correct, , scanner's name sc

please specific answer, because said, new @ java, , learning basics now. first big project.

thank you!

p.s. use eclipse code don't know if matters or not

* got 1 answer, , helpful, didn't work. here more of beginning of code may helpful in answering.

     import java.util.scanner;     public class bowling_score {       private static scanner sc; public static void main(string[] args) { //all variables     int frame1throw1 = 0;     int frame1throw2 = 0;     int frame2throw1 = 0;     int frame2throw2 = 0;     int frame3throw1 = 0;     int frame3throw2 = 0;     int frame4throw1 = 0;      //then have 1 variable each throw of game, , 1 final total score.         //directions     system.out.println("to put in score, put number of pins  knocked down in throw specified. if strike, enter 10 in first throw of frame , 0 in second throw of frame. if spare, ener 0 in first throw of frame , 10 in second throw of frame.");      //frame 1     system.out.println("frame 1, throw 1");     frame1throw1 = sc.nextint();     if (frame1throw1 == 10){         frame1throw1 = frame1throw1 + frame2throw1 + frame2throw2;         frame1throw2 = 0; }

a nullpointerexception means object referencing hasn't been initialised. in case imagine sc hasn't been created in code.

look like

scanner sc;

and change 

scanner sc = new scanner(system.in);

otherwise scope problem (you created object somewhere can't seen method) you'll need provide more code if first solution doesn't work.


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