BerLinux

Códigos del capitulo 1.

Archivo: Example.java

/*
This is a simple Java program.

Call this file Example.java.
*/
class Example {
// A Java program begins with a call to main().
public static void main(String[] args) {
System.out.println("Java drives the Web.");
}
}

Archivo: Example2.java

/*
This demonstrates a variable.

Call this file Example2.java.
*/
class Example2 {
public static void main(String[] args) {
int myVar1; // this declares a variable
int myVar2; // this declares another variable

myVar1 = 1024; // this assigns 1024 to myVar1

System.out.println("myVar1 contains " + myVar1);

myVar2 = myVar1 / 2;

System.out.print("myVar2 contains myVar1 / 2: ");
System.out.println(myVar2);
}
}

Archivo: Example3.java

/*
This program illustrates the differences
between int and double.

Call this file Example3.java.
*/
class Example3 {
public static void main(String[] args) {
int v; // this declares an int variable
double x; // this declares a floating-point variable

v = 10; // assign v the value 10

x = 10.0; // assign x the value 10.0

System.out.println("Original value of v: " + v);
System.out.println("Original value of x: " + x);

System.out.println(); // print a blank line

// now, divide both by 4
v = v / 4;
x = x / 4;

System.out.println("v after division: " + v);
System.out.println("x after division: " + x);
}
}

Archivo: GalToLit.java

/*
Try This 1-1

This program converts gallons to liters.

Call this program GalToLit.java.
*/
class GalToLit {
public static void main(String[] args) {
double gallons; // holds the number of gallons
double liters; // holds conversion to liters

gallons = 10; // start with 10 gallons

liters = gallons * 3.7854; // convert to liters

System.out.println(gallons + " gallons is " + liters + " liters.");
}
}

Archivo: IfDemo.java

/*
Demonstrate the if.

Call this file IfDemo.java.
*/
class IfDemo {
public static void main(String[] args) {
int a, b, c;

a = 2;
b = 3;

if(a < b) System.out.println("a is less than b");

// this won't display anything
if(a == b) System.out.println("you won't see this");

System.out.println();

c = a - b; // c contains -1

System.out.println("c contains -1");
if(c >= 0) System.out.println("c is non-negative");
if(c < 0) System.out.println("c is negative");

System.out.println();

c = b - a; // c now contains 1
System.out.println("c contains 1");
if(c >= 0) System.out.println("c is non-negative");
if(c < 0) System.out.println("c is negative");

}
}

Archivo: ForDemo.java

/*
Demonstrate the for loop.

Call this file ForDemo.java.
*/
class ForDemo {
public static void main(String[] args) {
int count;

for(count = 0; count < 5; count = count+1)
System.out.println("This is count: " + count);

System.out.println("Done!");
}
}

Archivo: BlockDemo.java

/*
Demonstrate a block of code.

Call this file BlockDemo.java.
*/
class BlockDemo {
public static void main(String[] args) {
double i, j, d;

i = 5;
j = 10;

// the target of this if is a block
if(i != 0) {
System.out.println("i does not equal zero");
d = j / i;
System.out.println("j / i is " + d);
}
}
}

Archivo: GalToLitTable.java

/*
Try This 1-2

This program displays a conversion
table of gallons to liters.

Call this program "GalToLitTable.java".
*/
class GalToLitTable {
public static void main(String[] args) {
double gallons, liters;
int counter;

counter = 0;
for(gallons = 1; gallons <= 100; gallons++) {
liters = gallons * 3.7854; // convert to liters
System.out.println(gallons + " gallons is " +
liters + " liters.");

counter++;
// every 10th line, print a blank line
if(counter == 10) {
System.out.println();
counter = 0; // reset the line counter
}
}
}
}

Códigos del capitulo 2.

Archivo: Inches.java

/*
Compute the number of cubic inches
in 1 cubic mile.
*/
class Inches {
public static void main(String[] args) {
long ci;
long im;

im = 5280 * 12;

ci = im * im * im;

System.out.println("There are " + ci +
" cubic inches in cubic mile.");

}
}

Archivo: Hypot.java

/*
Use the Pythagorean theorem to find
find the length of the hypotenuse
given the lengths of the two opposing
sides.
*/
class Hypot {
public static void main(String[] args) {
double x, y, z;

x = 3;
y = 4;

z = Math.sqrt(x*x + y*y);

System.out.println("Hypotenuse is " +z);
}
}

Archivo: CharArithDemo.java

// Character variables can be handled like integers.
class CharArithDemo {
public static void main(String[] args) {
char ch;

ch = 'X';
System.out.println("ch contains " + ch);

ch++; // increment ch
System.out.println("ch is now " + ch);

ch = 90; // give ch the value Z
System.out.println("ch is now " + ch);
}
}

Archivo: BoolDemo.java

// Demonstrate boolean values.
class BoolDemo {
public static void main(String[] args) {
boolean b;

b = false;
System.out.println("b is " + b);
b = true;
System.out.println("b is " + b);

// a boolean value can control the if statement
if(b) System.out.println("This is executed.");

b = false;
if(b) System.out.println("This is not executed.");

// outcome of a relational operator is a boolean value
System.out.println("10 > 9 is " + (10 > 9));
}
}

Archivo: Sound.java

/*
Try This 2-1

Compute the distance to a lightening
strke whose sound takes 7.2 seconds
to reach you.
*/
class Sound {
public static void main(String[] args) {
double dist;

dist = 7.2 * 1100;

System.out.println("The lightening is " + dist +
" feet away.");

}
}

Archivo: StrDemo.java

// Demonstrate escape sequences in strings.
class StrDemo {
public static void main(String[] args) {
System.out.println("First line\nSecond line");
System.out.println("A\tB\tC");
System.out.println("D\tE\tF");
}
}

Archivo: DynInit.java

// Demonstrate dynamic initialization.
class DynInit {
public static void main(String[] args) {
double radius = 4, height = 5;

// dynamically initializ volume
double volume = 3.1416 * radius * radius * height;

System.out.println("Volume is " + volume);
}
}

Archivo: ScopeDemo.java

// Demonstrate block scope.
class ScopeDemo {
public static void main(String[] args) {
int x; // known to all code within main

x = 10;
if(x == 10) { // start new scope
int y = 20; // known only to this block

// x and y both known here.
System.out.println("x and y: " + x + " " + y);
x = y * 2;
}
// y = 100; // Error! y not known here

// x is still known here.
System.out.println("x is " + x);
}
}

Archivo: VarInitDemo.java

// Demonstrate lifetime of a variable.
class VarInitDemo {
public static void main(String[] args) {
int x;

for(x = 0; x < 3; x++) {
int y = -1; // y is initialized each time block is entered
System.out.println("y is: " + y); // this always prints -1
y = 100;
System.out.println("y is now: " + y);
}
}
}

Archivo: NestVar.java

/*
This program attempts to declared a variable
in an inner scope with the same name as one
defined in an outer scope.

*** This program will not compile. ***
*/
class NestVar {
public static void main(String[] args) {
int count;

for(count = 0; count < 10; count = count+1) {
System.out.println("This is count: " + count);

int count; // illegal!!!
for(count = 0; count < 2; count++)
System.out.println("This program is in error!");
}
}
}

Archivo: ModDemo.java

// Demonstrate the % operator.
class ModDemo {
public static void main(String[] args) {
int iresult, irem;
double dresult, drem;

iresult = 10 / 3;
irem = 10 % 3;

dresult = 10.0 / 3.0;
drem = 10.0 % 3.0;

System.out.println("Result and remainder of 10 / 3: " +
iresult + " " + irem);
System.out.println("Result and remainder of 10.0 / 3.0: " +
dresult + " " + drem);

}
}

Archivo: RelLogOps.java

// Demonstrate the relational and logical operators.
class RelLogOps {
public static void main(String[] args) {
int i, j;
boolean b1, b2;

i = 10;
j = 11;
if(i < j) System.out.println("i < j");
if(i <= j) System.out.println("i <= j");
if(i != j) System.out.println("i != j");
if(i == j) System.out.println("this won't execute");
if(i >= j) System.out.println("this won't execute");
if(i > j) System.out.println("this won't execute");

b1 = true;
b2 = false;
if(b1 & b2) System.out.println("this won't execute");
if(!(b1 & b2)) System.out.println("!(b1 & b2) is true");
if(b1 | b2) System.out.println("b1 | b2 is true");
if(b1 ^ b2) System.out.println("b1 ^ b2 is true");
}
}

Archivo: SCops.java

// Demonstrate the short-circuit operators.
class SCops {
public static void main(String[] args) {
int n, d, q;

n = 10;
d = 2;
if(d != 0 && (n % d) == 0)
System.out.println(d + " is a factor of " + n);

d = 0; // now, set d to zero

// Since d is zero, the second operand is not evaluated.
if(d != 0 && (n % d) == 0)
System.out.println(d + " is a factor of " + n);

/* Now, try same thing without short-circuit operator.
This will cause a divide-by-zero error.
*/
if(d != 0 & (n % d) == 0)
System.out.println(d + " is a factor of " + n);
}
}

Archivo: SideEffects.java

// Side-effects can be important.
class SideEffects {
public static void main(String[] args) {
int i;

i = 0;

/* Here, i is still incremented even though
the if statement fails. */
if(false & (++i < 100))
System.out.println("this won't be displayed");
System.out.println("if statements executed: " + i); // displays 1

/* In this case, i is not incremented because
the short-circuit operator skips the increment. */
if(false && (++i < 100))
System.out.println("this won't be displayed");
System.out.println("if statements executed: " + i); // still 1 !!
}
}

Archivo: LtoD.java

// Demonstate automatic conversion from long to double.
class LtoD {
public static void main(String[] args) {
long L;
double D;

L = 100123285L;
D = L;

System.out.println("L and D: " + L + " " + D);

}
}

Archivo: DtoL.java

// *** This program will not compile. ***
class DtoL {
public static void main(String[] args) {
long L;
double D;

D = 100123285.0;
L = D; // Illegal!!!

System.out.println("L and D: " + L + " " + D);

}
}

Produce un error en la compilación

Archivo: CastDemo.java

// Demonstrate casting.
class CastDemo {
public static void main(String[] args) {
double x, y;
byte b;
int i;
char ch;

x = 10.0;
y = 3.0;

i = (int) (x / y); // cast double to int
System.out.println("Integer outcome of x / y: " + i);

i = 100;
b = (byte) i;
System.out.println("Value of b: " + b);

i = 257;
b = (byte) i;
System.out.println("Value of b: " + b);

b = 88; // ASCII code for X
ch = (char) b;
System.out.println("ch: " + ch);
}
}

Archivo: LogicalOpTable.java

/*
Try This 2-2

Print a truth table for the logical operators.
*/
class LogicalOpTable {
public static void main(String[] args) {

boolean p, q;

System.out.println("P\tQ\tAND\tOR\tXOR\tNOT");

p = true; q = true;
System.out.print(p + "\t" + q +"\t");
System.out.print((p&q) + "\t" + (p|q) + "\t");
System.out.println((p^q) + "\t" + (!p));

p = true; q = false;
System.out.print(p + "\t" + q +"\t");
System.out.print((p&q) + "\t" + (p|q) + "\t");
System.out.println((p^q) + "\t" + (!p));

p = false; q = true;
System.out.print(p + "\t" + q +"\t");
System.out.print((p&q) + "\t" + (p|q) + "\t");
System.out.println((p^q) + "\t" + (!p));

p = false; q = false;
System.out.print(p + "\t" + q +"\t");
System.out.print((p&q) + "\t" + (p|q) + "\t");
System.out.println((p^q) + "\t" + (!p));
}
}

Archivo: PromDemo.java

// A promotion surprise!
class PromDemo {
public static void main(String[] args) {
byte b;
int i;

b = 10;
i = b * b; // OK, no cast needed

b = 10;
b = (byte) (b * b); // cast needed!!

System.out.println("i and b: " + i + " " + b);
}
}

Archivo: UseCast.java

  // Using a cast.
class UseCast {
public static void main(String[] args) {
int i;

for(i = 0; i < 5; i++) {
System.out.println(i + " / 3: " + i / 3);
System.out.println(i + " / 3 with fractions: "
+ (double) i / 3);
System.out.println();
}
}
}

Códigos del capitulo 3.

Archivo: KbIn.java

// Read a character from the keyboard.

class KbIn {
public static void main(String[] args)
throws java.io.IOException {

char ch;

System.out.print("Press a key followed by ENTER: ");

ch = (char) System.in.read(); // get a char

System.out.println("Your key is: " + ch);
}
}

Archivo: Guess.java

// Guess the letter game.
class Guess {
public static void main(String[] args)
throws java.io.IOException {

char ch, answer = 'K';

System.out.println("I'm thinking of a letter between A and Z.");
System.out.print("Can you guess it: ");

ch = (char) System.in.read(); // read a char from the keyboard

if(ch == answer) System.out.println("** Right **");
}
}

Archivo: Guess2.java

// Guess the letter game, 2nd version.
class Guess2 {
public static void main(String[] args)
throws java.io.IOException {

char ch, answer = 'K';

System.out.println("I'm thinking of a letter between A and Z.");
System.out.print("Can you guess it: ");

ch = (char) System.in.read(); // get a char

if(ch == answer) System.out.println("** Right **");
else System.out.println("...Sorry, you're wrong.");
}
}

Archivo: Guess3.java

// Guess the letter game, 3rd version.
class Guess3 {
public static void main(String[] args)
throws java.io.IOException {

char ch, answer = 'K';

System.out.println("I'm thinking of a letter between A and Z.");
System.out.print("Can you guess it: ");

ch = (char) System.in.read(); // get a char

if(ch == answer) System.out.println("** Right **");
else {
System.out.print("...Sorry, you're ");

// a nested if
if(ch < answer) System.out.println("too low");
else System.out.println("too high");
}
}
}

Archivo: Ladder.java

// Demonstrate an if-else-if ladder.
class Ladder {
public static void main(String[] args) {
int x;

for(x=0; x<6; x++) {
if(x==1)
System.out.println("x is one");
else if(x==2)
System.out.println("x is two");
else if(x==3)
System.out.println("x is three");
else if(x==4)
System.out.println("x is four");
else
System.out.println("x is not between 1 and 4");
}
}
}

Archivo: SwitchDemo.java

// Demonstrate the switch.
class SwitchDemo {
public static void main(String[] args) {
int i;

for(i=0; i<10; i++)
switch(i) {
case 0:
System.out.println("i is zero");
break;
case 1:
System.out.println("i is one");
break;
case 2:
System.out.println("i is two");
break;
case 3:
System.out.println("i is three");
break;
case 4:
System.out.println("i is four");
break;
default:
System.out.println("i is five or more");
}

}
}

Archivo: NoBreak.java

// Demonstrate the switch without break statements.
class NoBreak {
public static void main(String[] args) {
int i;

for(i=0; i<=5; i++) {
switch(i) {
case 0:
System.out.println("i is less than one");
case 1:
System.out.println("i is less than two");
case 2:
System.out.println("i is less than three");
case 3:
System.out.println("i is less than four");
case 4:
System.out.println("i is less than five");
}
System.out.println();
}
}
}

Archivo: NoBreak1.java

class NoBreak1 {
public static void main(String[] args) {
int i;

for(i=0; i<=5; i++) {
switch(i) {

case 1:
case 2:
case 3: System.out.println("i is 1, 2 or 3");
break;
case 4: System.out.println("i is 4");
break;

}
System.out.println();
}
}
}

Archivo: Help.java

/*
Try This 3-1

A simple help system.
*/
class Help {
public static void main(String[] args)
throws java.io.IOException {
char choice;

System.out.println("Help on:");
System.out.println(" 1. if");
System.out.println(" 2. switch");
System.out.print("Choose one: ");
choice = (char) System.in.read();

System.out.println("\n");

switch(choice) {
case '1':
System.out.println("The if:\n");
System.out.println("if(condition) statement;");
System.out.println("else statement;");
break;
case '2':
System.out.println("The traditional switch:\n");
System.out.println("switch(expression) {");
System.out.println(" case constant:");
System.out.println(" statement sequence");
System.out.println(" break;");
System.out.println(" // ...");
System.out.println("}");
break;
default:
System.out.print("Selection not found.");
}
}
}

Archivo: SqrRoot.java

// Show square roots of 1 to 99 and the rounding error.

class SqrRoot {

public static void main(String[] args) {

double num, sroot, rerr;

for(num = 1.0; num < 100.0; num++) {

sroot = Math.sqrt(num);

System.out.println("Square root of " + num +

" is " + sroot);

// compute rounding error

rerr = num - (sroot * sroot);

System.out.println("Rounding error is " + rerr);

System.out.println();

}

Archivo: DecrFor.java

// A negatively running for loop.

class DecrFor {

public static void main(String[] args) {

int x;

for(x = 100; x > -100; x -= 5)

System.out.println(x);

}

Archivo: Comma.java

// Use commas in a for statememt.

class Comma {

public static void main(String[] args) {

int i, j;

for(i=0, j=10; i < j; i++, j--)

System.out.println("i and j: " + i + " " + j);

}

Archivo: ForTest.java

// Loop until an S is typed.

class ForTest {

public static void main(String[] args)

throws java.io.IOException {

int i;

System.out.println("Press S to stop.");

for(i = 0; (char) System.in.read() != 'S'; i++)

System.out.println("Pass #" + i);

}

Archivo: Empty.java

// Parts of the for can be empty.

class Empty {

public static void main(String[] args) {

int i;

for(i = 0; i < 10; ) {

System.out.println("Pass #" + i);

i++; // increment loop control var

}

Archivo: Empty2.java

// Move more out of the for loop.

class Empty2 {

public static void main(String[] args) {

int i;

i = 0; // move initialization out of loop

for(; i < 10; ) {

System.out.println("Pass #" + i);

i++; // increment loop control var

}

Archivo: Empty3.java

// The body of a loop can be empty.

class Empty3 {

public static void main(String[] args) {

int i;

int sum = 0;

// sum the numbers through 5

for(i = 1; i <= 5; sum += i++) ;

System.out.println("Sum is " + sum);

}

Archivo: ForVar.java

// Declare loop control variable inside the for.

class ForVar {

public static void main(String[] args) {

int sum = 0;

int fact = 1;

// compute the factorial of the numbers through 5

for(int i = 1; i <= 5; i++) {

sum += i; // i is known throughout the loop

fact *= i;

}

// but, i is not known here.

System.out.println("Sum is " + sum);

System.out.println("Factorial is " + fact);

}

Archivo: WhileDemo.java

// Demonstrate the while loop.

class WhileDemo {

public static void main(String[] args) {

char ch;

// print the alphabet using a while loop

ch = 'a';

while(ch <= 'z') {

System.out.print(ch);

ch++;

}

Archivo: Power.java

// Compute integer powers of 2.

class Power {

public static void main(String[] args) {

int e;

int result;

for(int i=0; i < 10; i++) {

result = 1;

e = i;

while(e > 0) {

result *= 2;

e--;

}

System.out.println("2 to the " + i + " power is " + result);

}

08/01/23

Archivo: DWDemo.java

// Demonstrate the do-while loop.

class DWDemo {

public static void main(String[] args)

throws java.io.IOException {

char ch;

do {

System.out.print("Press a key following by ENTER: ");

ch = (char) System.in.read(); // get a char

} while(ch != 'q');

}

Archivo: Guess4.java

// Guess the letter game, 4th version.

class Guess4 {

public static void main(String[] args)

throws java.io.IOException {

char ch, ignore, answer = 'K';

do {

System.out.println("I'm thinking of a letter between A and Z.");

System.out.print("Can you guess it: ");

// read a character

ch = (char) System.in.read();

// discard any other characters in the input buffer

do {

ignore = (char) System.in.read();

} while(ignore != '\n');

if(ch == answer) System.out.println("** Right **");

else {

System.out.print("...Sorry, you're ");

if(ch < answer) System.out.println("too low");

else System.out.println("too high");

System.out.println("Try again!\n");

}

} while(answer != ch);

}

09/01/23

BerLinux

viernes, 4 de agosto de 2023

Learning PHP, MySQL & JavaScript (Sixth Edition)

miércoles, 22 de junio de 2022

Java: A Beginner's Guide, Ninth Edition

Códigos del capitulo 1.

Códigos del capitulo 2.

Códigos del capitulo 3.

Learning PHP, MySQL & JavaScript (Sixth Edition)

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