Some good helpful java examples

*FACTORIAL* package javaapplication1; import java.util.Scanner; public class fact { public static void main(String[] args) { int a,c=1,i; Scanner sc=new Scanner(System.in); System.out.println("Enter number:"); a=sc.nextInt(); for(i=1;i<=a;i++) { c=c*i; System.out.println("c="+c); } } } *PALINDROME* package javaapplication1; public class palindrome { public static void main(String[] args) { int a=989,i; int t=1,t1=1,t2=1; for(i=0;i<10;i++) { t=a/100; t1=(a/10)-(t*10); t2=(a%100)-(t1*10); } System.out.println(t); System.out.println(t1); System.out.println(t2); if(t==t2) { System.out.println("it is a palindrome....!!!"); } else { System.out.println("it is not a palindrome...!! !"); } } } *PERMUTATION* package javaapplication2; import java.util.Scanner; class pc { void p() { int a,b,i,j,a1,b1; Scanner sc=new Scanner(System.in); System.out.print("Enter upper value:"); a=sc.nextInt(); System.out.print("Enter lower value:"); b=sc.nextInt(); a1=a; b1=b; for(i=1;i<a1;i++) { a=a*i; } for(j=1;j<b1;j++) { b=b*j; } int c; c=a/b; System.out.println("permutation:"+c); } void c() { int a,b,i,j,a1,b1,n,n1; Scanner sc=new Scanner(System.in); System.out.print("Enter upper value:"); a=sc.nextInt(); System.out.print("Enter lower value:"); b=sc.nextInt(); n=a-b; n1=n; a1=a; b1=b; for(int k=1;k<n1;k++) { n=n*k; } for(i=1;i<a1;i++) { a=a*i; } for(j=1;j<b1;j++) { b=b*j; } int c; c=a/b; int l; l=c/n; System.out.println("Combination:"+l); } } public class p_c { public static void main(String[] args) { pc v=new pc(); String s; Scanner sc=new Scanner(System.in); System.out.println("Enter op:"); s=sc.next(); if("permutation".equals(s)) v.p(); else if("combination".equals(s)) v.c(); else System.out.println("ERROR 402"); } } *SQUARE ROOT* package javaapplication2; import java.util.Scanner; public class sqrt { public static void main(String[] args) { int a; Scanner sc=new Scanner(System.in); System.out.print("Enter a:"); a=sc.nextInt(); double k; k=Math.pow(a,0.5); System.out.println("Square root of "+a+" is "+ k); } } *FILE WRITER AND FILE READER* package vansh1; import java.io.BufferedReader; import java.io.FileReader; import java.io.FileWriter; import java.nio.Buffer; import java.nio.file.Files; import java.nio.file.Path; import java.util.List; public class NewClass { public static void main(String[] args) { int ch; try { FileWriter fw=new FileWriter("vansh.txt"); for(int i=0;i<2;i++){ fw.write("vansh"); } fw.close(); } catch (Exception e) { e.printStackTrace(); } } } *ASCENDING ORDER* package vansh1; public class asc { public static void main(String[] args) { int a[]={8,9,2,87,55,67,43}; int t,i; for(i=0;i a[j]) { t=a[i]; a[i]=a[j]; a[j]=t; } } for(i=0;i<a.length;i++) { System.out.println(a[i]); } } } *CALCULATOR* package vansh1; import jdk.internal.dynalink.DefaultBootstrapper; public class calc { public static void sum() { int a=10,b=20; int c=a+b; System.out.println("sum:"+c); } public static void sub() { int a=50,b=20; int c=a-b; System.out.println("sub:"+c); } public static void mul() { int a=80,b=56; int c=a*b; System.out.println("product:"+c); } public static void div() { int a=85,b=5; int c=a/b; System.out.println("Division:"+c); } public static void main(String[] args) { sum(); sub(); mul(); div(); } } *PROGRAM* package vansh1; public class pro1 { public static void dis() { int i=10,j=20,k; k=i+j; System.out.println("sum : "+k); } public static int dis1() { int i=10,j=20,k; k=i+j; return k; } public static void dis2(int i,int j) { int k; k=i+j; System.out.println("sum2 : "+k); } public static int dis3(int i,int j) { int k=i+j; return k; } public static void main(String[] args) { int k,a=10,b=20; dis(); k=dis1(); System.out.println("sum1 : "+k); dis2(a,b); int c; c=dis3(a,b); System.out.println("sum3 :"+c); } }