Java language Basics

Tag: The Java language is missing even. com consolidation length End-128 odd

Output error message and debug information

Package com;
public class MSJ {
public static void Main (string[] args) {
SYSTEM.OUT.PRINTLN (the "main () method starts running. ");
Output error message
SYSTEM.ERR.PRINTLN ("Manually output an error message during run time:");
System.err.println ("\ t this software does not buy insurance, please pay attention to security");
System.out.println ("Printerroranddebug.main ()");
SYSTEM.OUT.PRINTLN (the "main () method runs the end. ");
}
}

Results:

To receive input characters from the console

Package com;

Import Java.util.Scanner;

public class MSJ {
public static void Main (string[] args) {
Scanner Scanner = new Scanner (system.in);//create an input stream scanner
System.out.println ("Please enter your ID number:");//Prompt user to enter
String line = Scanner.nextline ();//Gets the text of a row entered by the user
Print a description of the input text
System.out.println ("Original your ID number is" + line.length () + "digits of ah");
}
}

Results:

REDIRECT Output stream Realization program log

Package com;

Import java.io.FileNotFoundException;
Import Java.io.PrintStream;
Import Java.util.Scanner;

public class MSJ {
public static void Main (string[] args) {
try {
PrintStream out = system.out;//Save the original output stream
PrintStream ps=new PrintStream ("./log.txt");//create file output stream
System.setout (PS);//Set up with a new output stream
int age=18;//defining shaping variables
SYSTEM.OUT.PRINTLN ("Age variable is defined successfully, initial value is 18");
String sex= "female";//define string variable
SYSTEM.OUT.PRINTLN ("The gender variable is defined successfully, the initial value is female");
Consolidation of two variables
String info= "This is a" +sex+ "child, should have" +age+ "years old. ";
System.out.println ("consolidates two variables as info string variable, the result is:" +info);
System.setout (out);//restore Original output stream
SYSTEM.OUT.PRINTLN ("The program has finished running, please review the log file. ");
} catch (FileNotFoundException e) {
E.printstacktrace ();
}
}
}

Results:

Automatic type conversions and forced type conversions

Package com;
public class MSJ {
public static void Main (string[] args) {
byte B = 127;
char c = ' W ';
Short S = 23561;
int i = 3333;
Long L = 400000L;
float F = 3.14159F;
Double d = 54.523;
Automatic conversion of low type to high type
SYSTEM.OUT.PRINTLN ("Cumulative byte equals:" + B);
SYSTEM.OUT.PRINTLN ("Cumulative char equals:" + (b + c));
SYSTEM.OUT.PRINTLN ("Cumulative short equals:" + (b + C + s));
SYSTEM.OUT.PRINTLN ("additive int equals:" + (b + C + S + i));
SYSTEM.OUT.PRINTLN ("Additive long equals:" + (b + C + S + i + L));
SYSTEM.OUT.PRINTLN ("Cumulative float equals:" + (b + C + S + i + L + f));
SYSTEM.OUT.PRINTLN ("Cumulative double equals:" + (b + C + S + i + L + F + D));
High-type to low-type casts
System.out.println ("Converts a long cast type to int:" + (int) l);
High type to low type conversion can lose data
SYSTEM.OUT.PRINTLN ("Convert int coercion type to short:" + (short) l);
Real to integer conversions will discard fractional parts
System.out.println ("Converts the double coercion type to int:" + (int) d);
integer-to-character-type conversions get the corresponding encoded characters
System.out.println ("Convert the short coercion type to char:" + (char) s);
}
}

Results:

Encryption can be as simple as this (bit operation)

Package com;

Import Java.util.Scanner;

public class MSJ {
public static void Main (string[] args) {
Scanner scan = new Scanner (system.in);
System.out.println ("Please enter the string to encrypt");
String password = scan.nextline ();//Get user input
char[] array = Password.tochararray ();//Get character array
for (int i = 0; i < Array.Length; i++) {//Traversal character array
Array[i] = (char) (Array[i] ^ 20000);//An XOR operation on each array element
}
SYSTEM.OUT.PRINTLN ("Encrypted results are as follows:");
System.out.println (new String (array));//Output encryption information
Password=new String (array);
Array = Password.tochararray ();//Get character array
for (int i = 0; i < Array.Length; i++) {//Traversal character array
Array[i] = (char) (Array[i] ^ 20000);//An XOR operation on each array element
}
System.out.println ("Decryption results are as follows:");
System.out.println (new String (array));//Output decryption information
}
}

Results

Judging odd and even numbers with ternary operators

Package com;

Import Java.util.Scanner;

public class MSJ {
public static void Main (string[] args) {
Scanner scan = new Scanner (system.in);//create an input stream scanner
System.out.println ("Please enter an integer:");
Long number = Scan.nextlong ();//Gets the integer entered by the user
String check = (number% 2 = = 0)? "This number is: even": "This number is: odd";
SYSTEM.OUT.PRINTLN (check);
}
}

Results:

Multiplication is not implemented without multiplication operators

Package com;

Import Java.util.Scanner;

public class MSJ {
public static void Main (string[] args) {
Scanner scan=new Scanner (system.in);//Create Scanner
System.out.println ("Please enter an integer");
Long number = Scan.nextlong ();//Gets the input integer
System.out.println ("The number you entered is:" +number);
System.out.println ("The number is multiplied by 2 for the result:" + (number<<1));
System.out.println ("The number is multiplied by 4 for the result:" + (NUMBER<<2));
System.out.println ("The number is multiplied by 8 for the result:" + (number<<3));
System.out.println ("The number is multiplied by 16 for the result:" + (number<<4));
}
}

Results:

Implements the interchange of two variables (without the help of the 3rd variable)

Package com;

Import Java.util.Scanner;

public class MSJ {
public static void Main (string[] args) {
Scanner scan = new Scanner (system.in);//Create Scanner
System.out.println ("Please enter the value of variable a");
Long A = Scan.nextlong ();//Receive first value of variable
System.out.println ("Please enter the value of variable B");
Long B = Scan.nextlong ();//Receive second value of variable
System.out.println ("a=" + A + "\tb=" + B);
SYSTEM.OUT.PRINTLN ("Perform variable interchange ...");
A = a ^ b;//performing variable swaps
b = b ^ A;
A = a ^ B;
System.out.println ("a=" + A + "\tb=" + B);
}
}

Java language Basics