Randomizing text file read in Java -

i trying read text file in java, set of questions. 4 choices , 1 answer. structure looks this:

question

option a

option b

option c

option d

answer

i have no trouble reading way:

public class rar{ public static string[] q=new string[50]; public static string[] a=new string[50]; public static string[] b=new string[50]; public static string[] c=new string[50]; public static string[] d=new string[50]; public static char[] ans=new char[50]; public static scanner sr= new scanner(system.in);   public static void main(string args[]){ int score=0; try {              filereader fr;       fr = new filereader (new file("f:\\questions.txt"));       bufferedreader br = new bufferedreader (fr); int ar=0;       for(ar=0;ar<2;ar++){       q[ar]=br.readline();       a[ar]=br.readline();       b[ar]=br.readline();       c[ar]=br.readline();       d[ar]=br.readline();     string tempo=br.readline();     ans[ar]=tempo.charat(0);               system.out.println(q[ar]);         system.out.println(a[ar]);         system.out.println(b[ar]);         system.out.println(c[ar]);         system.out.println(d[ar]);         system.out.println("answer: ");         string strans=sr.nextline(); char y=strans.charat(0); if(y==ans[ar]){     system.out.println("check!"); score++; system.out.println("score:" + score); }else{ system.out.println("wrong!"); }        }       br.close();     } catch (exception e) { e.printstacktrace();}   }     } 

the code above predictable. loop increments. , displays questions based on order.

what want able randomize through text file, still maintaining same structure. (q, a, b, c, d, ans). when try this:

int ran= random(1,25);    system.out.println(q[ran]);         system.out.println(a[ran]);         system.out.println(b[ran]);         system.out.println(c[ran]);         system.out.println(d[ran]);         system.out.println("answer: ");         string strans=sr.nextline(); char y=strans.charat(0); if(y==ans[ran]){     system.out.println("check!"); score++; system.out.println("score:" + score); }else{ system.out.println("wrong!"); } 

and method use randomizing:

public static int random(int min, int max){     int xx;     xx= (int) ( math.random() * (max-min + 1))+ min;     return xx;     } 

there's possibility null. can recommend no null when trying randomize questions?

can see else wrong program?

you use kind of magic numbers, numbers in code don't make sense.

public static string[] q=new string[50]; //why make array hold 50 questions?  //...   for(ar=0;ar<2;ar++){ //why read 2 questions?  //...  int ran= random(1,25); //why take 1 of 25 questions? system.out.println(q[ran]); 

these should same number, right? if have 25 questions, should have room 25, read 25 , use 25.

how fix this:

1 make constant

public final static int number_of_questions = 25; 

then use when making array, reading questions , when taking random one:

public static string[] q=new string[number_of_questions];  for(ar=0;ar<number_of_questions;ar++){  int ran= random(1,number_of_questions); 

2 use q.length

public static string[] q=new string[number_of_questions];  for(ar=0;ar<q.length;ar++){  int ran= random(1,q.length); 

3 use list / collection

public static list<string> q=new list<string>();  for(ar=0;ar<q.size();ar++){  int ran= random(1,q.size()); 

option 3 best choice, java afterall. see mike's answer more detail in making more java.