java - Passing arrays as parameters and make calculations -

i have make java program, user type in total numbers of students, made code:

import java.util.*; import java.lang.*; import java.io.*;  /* name of class has "main" if class public. */ class ideone {     public static void main (string[] args) throws java.lang.exception     {         // code goes here         int numreaders = 0;         scanner scan = new scanner(system.in);         system.out.println("enter number of magazin readers:");         numreaders = scan.nextint(); 

now, after adding total number of students, should add names array:

//creating array of names, length total number entered user         string[] namestr = new string[numreaders];         int[] ages = new int[numreaders];         for(int i=0; i<numreaders; i++)         {             scanner n = new scanner(system.in);             system.out.println("enter name of reader: "+i);             namestr[i] = n.next();          } 

after that, should add correspondingly age of each name, made portion of code:

for(int i=0; i<numreaders; i++)         {             scanner = new scanner(system.in);             system.out.println("enter age of reader: "+i);             ages[i] = a.nextint();         }          //display results         system.out.println("number of readers is: "+numreaders);         (int i=0; i<numreaders; i++)         {             system.out.println("the name of reader "+i+" "+namestr[i]+ " , age "+ages[i]);         }  

after making code, tested using ideone , command prompt , works properly:

now, need call method according selection of user: if typed 'a' method should called specify name , age of oldest student. if typed 'b' method called see how many students have age specified user , if typed 'c', function called calculate average age of them all.

i new methods don't know how add arrays methods , make statements.

here full code:

/* package whatever; // don't place package name! */  import java.util.*; import java.lang.*; import java.io.*;  /* name of class has "main" if class public. */ class ideone {     public static void main (string[] args) throws java.lang.exception     {         // code goes here         int numreaders = 0;         scanner scan = new scanner(system.in);         system.out.println("enter number of magazin readers:");         numreaders = scan.nextint();          //creating array of names, length total number entered user         string[] namestr = new string[numreaders];         int[] ages = new int[numreaders];         for(int i=0; i<numreaders; i++)         {             scanner n = new scanner(system.in);             system.out.println("enter name of reader: "+i);             namestr[i] = n.next();          }         for(int i=0; i<numreaders; i++)         {             scanner = new scanner(system.in);             system.out.println("enter age of reader: "+i);             ages[i] = a.nextint();         }          //display results         system.out.println("number of readers is: "+numreaders);         (int i=0; i<numreaders; i++)         {             system.out.println("the name of reader "+i+" "+namestr[i]+ " , age "+ages[i]);         }          //choosing statistic         //if a:         system.out.println("please choose a, b or c:");         scanner stat = new scanner(system.in);         char x;         x = stat.next().charat(0);         if(x=='a')         system.out.println(x+x);         else if(x=='b')         //system.out.println(x);             //scanner newage = new scanner(system.in);             //int agetosearchfor = newage.nextint();             //maxage(agetosearchfor);         else         system.out.println(x);     } } 

right, start user enters input, example 'a', let's go this:

firstly, need create method name of oldest student displayed, let's call 'getoldeststudent' - when naming methods typical naming convention, starting lowercase , moving uppercase each new word - try , make them intuitive possible.

when making method signature, need give visibility , going return. in case, using 1 class, give private, visible class.

now need return 2 things, can either put these string or put them array, recommend, going return array. however, want input array search through, goes in tbe brackets parameters (or arguments). therefore our method signature following:

private string[] getoldeststudent(string[] students, int[] ages) 

then inside method, can code need find oldest student, add name , age array , return this.

need anymore drop comment.

on side note, have been better off creating 'student' object , giving object 'name' property , 'age' property , making array of students , getters , setters (or accessors , mutators) these properties.