02 Java Language And OOP PART II

Java Language and OOP Part II

By Hari Christian

Agenda

• 01 Operator in Java• 02 Operator - Assignment• 03 Operator - Relational• 04 Operator - Arithmetic• 05 Operator - Conditional• 06 Operator - Bitwise• 07 Operator - Logical• 08 Operator - Precedence• 09 Operator - Associativity

Agenda

• 10 Selection Statement - If• 11 Selection Statement - Switch• 12 Selection Statement - Conditional• 13 Looping Statement - For• 14 Looping Statement - While• 15 Looping Statement - Do While• 16 Continue Statement• 17 Break Statement• 18 Basic of Arrays• 19 Arrays of Arrays

Operator

• An operator is a punctuation mark that says to do something to two (or three) operands

• An example is the expression "a * b". The "*" is the multiplication operator, and "a" and "b" are the operands

Operator

• Example:

int a = 3 * 2;

int b = 3 + t.calculate();

arr[2] = 5;

arr[2+5] = 2 + 5;

Operator - Assignment

• Using notation equal (=)

• This Operator using two operand, left operand and right operand

• Expression on the right operand is evaluated and the result stored in left operand

Operator - Assignment

int num1 = 5; // Assign value 5 to num1

int num2 = num2 + 5; // Add value 5 to num2

int num3 += 5; // Add value 5 to num3

int num4 = num4 - 5; // Substract 5 to num4

int num5 -= 5; // Substract 5 to num5

int num6 = num6 * 5; // Multiply 5 to num6

int num7 *= 5; // Multiply 5 to num7

int num8 = num8 / 5; // Divide 5 to num8

int num9 /= 5; // Divide 5 to num9

Operator - Relational

• Relational Operator always give a boolean result (true or false)

• 6 Relational Operator:Operator Description

< Less than

> More than

<= Less than or Equal

>= More than or Equal

== Comparison

!= Not equal


int num1 = 5;

if (num1 < 5) {

System.out.println(“Less than 5”);

}

if (num1 > 5) {

System.out.println(“More than 5”);

}


int num1 = 5;

if (num1 <= 5) {

System.out.println(“Less than or equal 5”);

}

if (num1 >= 5) {

System.out.println(“More than or equal 5”);

}


int num1 = 5;

if (num1 == 5) {

System.out.println(“Equal 5”);

}

if (num1 != 5) {

System.out.println(“Not equal 5”);

}

Operator – Instance Of

class Vehicle {}

class Car extends Vehicle {}

class Mercedes extends Car {}

Vehicle v = new Vehicle();

Mercedes m = new Mercedes();

if (m instanceof Vehicle) {

System.out.println(“m is Vehicle");

}

if (v instanceof Mercedes) {

System.out.println(“v is Mercedes");

}

Operator - Arithmetic

• Arithmetic Operator just like a Math!!!

• 7 Arithmetic Operator:Operator Description

+ Addition

- Substraction

* Multiplication

/ Divide

% Modulus

++ Increment by 1

-- Decrement by 1

Operator - Arithmetic

int addition = 5 + 5;

int substraction = 5 - 5;

int multiplication = 5 * 5;

int divide = 5 / 5;

int modulus = 5 % 5; // 100 % 17 = ?

int num = 5;

int preIncrement = ++num;

int postIncrement = num++;

int preDecrement = --num;

int postDecrement = num++;

Operator - Conditional

• Also called Ternary Operator

• This operator using notation ? and :

• Example:

int num1 = (5 == 5) ? 0 : 1;

int num2 = (5 != 5) ? 0 : 1;

int num3 = (5 < 5) ? 0 : 1;

int num4 = (5 > 5) ? 0 : 1;

Operator - Bitwise

int a = 60; /* 60 = 0011 1100 */

int b = 13; /* 13 = 0000 1101 */

c = a & b; /* 12 = 0000 1100 */

c = a | b; /* 61 = 0011 1101 */

c = a ^ b; /* 49 = 0011 0001 */

c = ~a; /*-61 = 1100 0011 */

c = a << 2; /* 240 = 1111 0000 */

c = a >> 2; /* 215 = 1111 */

c = a >>> 2; /* 215 = 0000 1111 */

Operator - Logical

• To combine other operator

• 2 Relational Operator:

Operator Description

&& And

|| Or

Operator – Logical And

• AND Combination table

Operator 1 Operator 2 Result

False False False

False True False

True False False

True True True


• Example:

int num = 5;

if (num == 6 && num > 10) { // false and false

System.out.println(“Hari Christian”);

}

if (num == 6 && num > 2) { // false and true


}


• Example:

int num = 5;

if (num == 5 && num > 10) { // true and false


}

if (num == 5 && num > 2) { // true and true


}

Operator – Logical Or

• OR Combination table

Operator 1 Operator 2 Result

False False False

False True True

True False True

True True True


• Example:

int num = 5;

if (num == 6 || num > 10) { // false and false


}

if (num == 6 || num > 2) { // false and true


}


• Example:

int num = 5;

if (num == 5 || num > 10) { // true and false


}

if (num == 5 || num > 2) { // true and true


}

Operator - Precedence

– calories

Symbol Note Precedence

++ -- pre-increment or decrement 16

++ -- post-increment or decrement 15

~ flip the bits of an integer 15

! logical not 14

- + arithmetic negation or plus 14

(typename) type conversion or cast 13

* / % multiplicative operators 12

- + additive operators 11

<< >> >>> left and right bitwise shift 10

Operator - Precedence

– calories

Symbol Note Precedence

instanceof< <= > >=

relational operators 9

== != equality operators 8

& bitwise and 7

^ bitwise exclusive or 6

| bitwise inclusive or 5

&& conditional and 4

|| conditional or 3

? : conditional operator 2

= *= /= %= += -= <<= >>= >>>= &= ^= |=

assignment operators 1

Operator - Associativity

– calories

Symbol Note Precedence Associativity

++ -- pre-increment or decrement 16 right

++ -- post-increment or decrement 15 left

~ flip the bits of an integer 15 right

! logical not 14 right

- + arithmetic negation or plus 14 right

(typename) type conversion or cast 13 right

* / % multiplicative operators 12 left

- + additive operators 11 left

<< >> >>> left and right bitwise shift 10 left

Operator - Associativity

– calories

Symbol Note Precedence Associativity

instanceof< <= > >=

relational operators 9 left

== != equality operators 8 left

& bitwise and 7 left

^ bitwise exclusive or 6 left

| bitwise inclusive or 5 left

&& conditional and 4 left

|| conditional or 3 left

? : conditional operator 2 right

= *= /= %= += -= <<= >>= >>>= &= ^= |=

assignment operators 1 right

Selection Statement - IF

• Format:

if ( Expression ) Statement [ else Statement ]

• Explanation: Expression must have boolean type Using { } to make more than 1 statement


• Example:

boolean valid = false;

if (valid = true) {

System.out.println(“VALID”);

} else {

System.out.println(“TIDAK VALID”);

}


• Example:


if (valid) {


} else {


}


• Example:


if (valid == true) {


} else {


}


• Example:int number = 5;

if (number == 5) {

System.out.println(“PT”);

}

if (number > 2) {

System.out.println(“GUNATRONIKATAMA”);

}

if (number > 5) {

System.out.println(“CIPTA”);

} else {

System.out.println(“LESTARI”);

}



if (number == 5) {

System.out.println(“PT”);

} else if (number > 2) {

System.out.println(“GUNATRONIKATAMA”);

} else if (number > 4) {

System.out.println(“CIPTA”);

} else {

System.out.println(“LESTARI”);

}



String result = number == 1 ? “a” : “b”;

OR

String result = number == 1 ? “satu” : number == 2? “dua” : “bukan dua”;

System.out.println(“number = “ + number);

Selection Statement - Switch

• Format:

switch ( Expression ) {

case constant_1 : Statement; break;



case constant_n : Statement; break;

default : Statement; break;

}


• Explanation: Cannot have same expression Default is optional, but bear in mind there can be only

one default Default doesn’t have to be last



String a = “”;

switch (x) {

case 1: a = “PT”;

case 2: a = “GUNATRONIKATAMA”;

case 3: a = “CIPTA”;

case 4: a = “JAYA”;

case 5: a = “LESTARI”;

default: a = “MAKMUR”;

}



String a = “”;

switch (x) {

case 1: a = “PT”; break;

case 2: a = “GUNATRONIKATAMA”; break;

case 3: a = “CIPTA”; break;

case 4: a = “JAYA”; break;

case 5: a = “LESTARI”; break;

default: a = “MAKMUR”; break;

}

Looping Statement - For

• Format:

for ( Initial; Test; Increment ) Statement

• New Format (since Java 5):

for ( Object object : Array) Statement


• Example:

int i;

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

// loop body

}

OR

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

// loop body

}


• Example:

for (int i = 0; i < employees.size(); i++) {

Employee e = employees.get(i);

e.getName();

}

OR

for (Employee e : employees) { // new

e.getName();

}


• Infinite loop

for ( ;; ) {

}

Looping Statement - While

• Format:

while ( Expression ) Statement

• Explanation: While boolean Expression remain true, the Statement

is executed If Expression is false on first evaluation, the

Statement will not execute

Looping Statement - While

• Example:

int i = 0;

while (i < 10) {

// loop body

i++;

}

Looping Statement – Do While

• Format:

do Statement while ( Expression )

• Explanation: While boolean Expression remain true, the Statement

is executed If Expression is false on first evaluation, the

Statement will execute once

Looping Statement – Do While

• Example:

int i = 0;

do {

// loop body

i++;

} while (i < 10) ;

Looping Statement – Continue

• Format:

continue;

continue Identifier;

• Explanation: Continue occur only in loops When a continue statement executed, it will pass to

the next iteration of the loop

Looping Statement - Continue

• Example:

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

if (i == 5) {

continue;

}

}

Looping Statement - Continue

• Example:

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

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

if (j == 5) continue gasi;}

}

Looping Statement – Break

• Format:

break;

break Identifier;

• Explanation: When a break statement executed, it will break or

exit the loop

Looping Statement - Break

• Example:

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

if (i == 5) {

break;

}

}


• Example:

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

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

if (j == 5) break gasi;}

}


• Example:

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

System.out.println(“i = “ + i);

for (int j = 0; j < 5; j++) {

System.out.println(“j = “ + j);

if (j == 2) break;

}

if (i == 3) break;

}

Basic of Arrays

• Arrays are objects it means array types are reference types, and your array variable is really a reference to an array

• Here are some ways in which arrays are like objects:– They are objects because the language specification says so

("An object is a class instance or an array", section 4.3.1)– Array types are reference types, just like object types– Arrays are allocated with the "new" operator, similar to

constructors– Arrays are always allocated in the heap part of memory, never in

the stack part of memory. Objects follow the same rule

Basic of Arrays

• We can define an Arrays of:– Primitive Data Type– Object

• Index of Array ALWAYS start with zero

• To get size of Arrays we use array.length

Basic of Arrays

• Declare an Arrays:

// Recommended

int[] data;

int[] data1, data2, data3;

// Not recommended

int data[];

int data1[], data2[], data3[];

Basic of Arrays

• Initialize an Arrays:

int[] data;

data = new int[10]; // Valid

data = new int[]; // Invalid

int[] data = new int[10]; // Valid

int[10] data = new int[10]; // Invalid

int data[10] = new int[10]; // Invalid

int data[10]; // Invalid

Basic of Arrays

• Fill an Arrays:

int[] data = new int[5]; // Valid

data[0] = 5; // OK

data[1] = 6;

data[2] = 7;

data[3] = 8;

data[4] = 9; // OK … so far

data[5] = 10; // We have a problem here

Basic of Arrays

• Fill an Arrays:

int[] data = {6, 7, 8, 9, 10}; // Valid

int[] data = new int[] {6, 7, 8, 9, 10}; // Valid

int[] data = new int[5] {6, 7, 8, 9, 10}; // Invalid

int[] data = new int[5];

data = {6, 7, 8, 9, 10}; // Invalid

Arrays of Arrays

• In other language called Multi Dimension Arrays– The Visual Basic language only has multidimensional

arrays, and only calls them multidimensional arrays– The ANSI C standard says C has what other

languages call arrays of arrays, but it also calls these multidimensional

– The Ada standard explicitly says arrays of arrays and multidimensional arrays are different. The language has both

– The Pascal standard says arrays of arrays and multidimensional arrays are the same thing

Arrays of Arrays

• Declare an Arrays:

// Recommended

int[][] data;

int[][] data1, data2, data3;

// Not recommended

int data[][];

int data1[][], data2[][], data3[][];

Arrays of Arrays

• Initialize an Arrays:

int[][] data;

data = new int[10][10]; // Valid

data = new int[10][]; // Invalid

int[][] data = new int[10][10]; // Valid

int[10][10] data = new int[10][10]; // Invalid

int data[10][10] = new int[10][10]; // Invalid

int data[10][10]; // Invalid

Arrays of Arrays

• Fill an Arrays:

int[][] data = new int[3][3];data[0][0] = 0;

data[0][1] = 1;

data[0][2] = 2;

data[1][0] = 0;

data[1][1] = 1;

data[1][2] = 2;

data[2][0] = 0;

data[2][1] = 1;

data[2][2] = 2;

Arrays of Arrays

• Fill an Arrays:

int[][] data = new int[3][];data[0] = new int[1];

data[0][0] = 0;

data[1] = new int[2];

data[1][0] = 0;

data[1][1] = 1;

data[2] = new int[3];

data[2][0] = 0;

data[2][1] = 1;

data[2][2] = 2;

Arrays of Arrays

• Fill an Arrays:

int[][] data = {{0, 1}, {0, 1, 2}, {0, 1, 2, 3}}; // Valid

int[][] data = new int[][] {{0, 1}, {0, 1}}; // Valid

int[][] data = new int[1][2] {{0, 1}}; // Invalid

int[][] data = new int[2][2];

data = {{0, 1}, {1, 2}, {2, 3}}; // Invalid

Thank You

02 Java Language And OOP PART II

Software

operator logical

operator logical

operator bitwise int

operator example

operator conditional

conditional operator

operator description

multiplication operator