Selenium 13: Java Control Flow Statements Part-2, String Handling

Java Control Flow Statements Part-2, String Handling, Java Looping Statements, do while loop and Java Enhanced for loop. Java Branching Statements, break statement, continue statement, and return statement. String handling in Java, What is String?, Creating Strings, and String Operations in Java (String Concatenation, String Comparison, and Fine String Length).

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Class Notes:
Selenium Class 13: Java Control Flow Statements Part-2, String Handling

i) Java Control Flow Statements Part-2
ii) String Handling in Java

i) Java Control Flow Statements Part-2
i) Decision Making Statements (if, switch statements)
ii) Looping Statements (for, while, do while, and enhanced for loop)
iii) Branching Statements (break, continue, return)

Looping Statements
1) for loop
2) while loop

3) do while loop

It repeats a block of statements while condition is true
It executes statements at least once irrespective of the condition

Syntax:

Initialization
do
{
Statements


Increment/Decrement
} while (condition);

Print 1 to 10 Numbers
Print 10 to 1 Numbers
Print 1 to 5 Numbers except 4th number,

int i=1;
do
{
System.out.println(i);
i++;
} while (i<=10);

int i=10;
do
{
System.out.println(i);
i--;
} while (i>=1);

int i=10;
do
{
System.out.println(i);
i--;
} while (i>=1);

int i=1;
do
{
if (i != 4){
System.out.println(i);
}
i++;
} while (i<=5);

4) Enhanced for loop

Syntax:

It executes all elements in an Array

Array Declaration;
for (declaration: Expression/Array){
Statements



}

Example:
String [] languages = {"C", "COBOL", "Java", "VBScript"};

for (String lang: languages){
System.out.println(lang);
}

int a=10, b=20;
int [] mathOperations = new int[3];
mathOperations[0]=a+b;
mathOperations[1]=a-b;
mathOperations[2]=a*b;

for (int operation: mathOperations){

}

int [] mathOperations = new int[3];
mathOperations[0]=a+b;

for (int operation: mathOperations){

}

3) Branching Statements

> Branching Statements are used to transfer control from one point to another in the code
> Branching Statements are defined by the three keywords- break, continue, and return.

1) break

> break statement is used to stop the execution and comes out of loop.
> Mostly break statement used in switch, and in loops also we can use it.

Example:
for (int i=1; i<=10; i++){
System.out.println(i);
if (i == 4){
break;
}

2) continue

continue statement is also same as break statement, the only difference is when break statement executes it comes out of loop, whereas continue statement comes out from the loop temporarily.

Example:
for (int i=1; i<=10; i++){
if (i%2 == 0){
continue;
}
System.out.println(i);
}

3) return

return statement is used in user defined methods (methods with return value), which returns a value or statement from current to calling return statement must be always last statement in the method.

Example:
public int add(int a, int b){
int result = a+b;
return result;
}
public static void main(String[] args) {
VariablesOperators sirisha = new VariablesOperators();
int d= sirisha.add(10, 30);
System.out.println(d);//40
System.out.println(sirisha.add(10, 40));//50

public class VariablesOperators {
public static void main(String[] args) {
VariablesOperators sirisha = new VariablesOperators();
int d= sirisha.add(10, 30);
System.out.println(d);//40
System.out.println(sirisha.add(10, 40));//50
}
public int add(int a, int b){
int result = a+b;
return result;
}

}

Note:
> Write user defined methods before main method or after main method (with in class only)
> Call user defined (Non-static) methods within main method only
> Don't write user defined methods within main method.

ii) String Handling in Java

What is String?

String is a sequence of characters written in double quotes

Syntax:

String stringName = "value";

String may have Alphabets, Numbers, and Special Characters

String a="India";
String b= "100";
String c ="India123";
String d ="*&%$";
String e = "123*&%$";
String f ="India123*&%$";
String g="Selenium With Java"

In VBScript:
Dim a
a=100 'Internally VBScript considers this data as Integer type data
.
.
a=12.345 'Internally VBScript considers this data as Double type data
.
.
.
a=#10/10/201# 'Internally VBScript considers this data as Date type data
.
.
.
a="Vijaya" 'Internally VBScript considers this data as String type data

Operations on Strings

1) Concatenating Strings

String + String - Concatenation
String + Integer - Concatenation
Integer + Integer - Addition

String str1 = "Selenium";
String str2="Testing";

System.out.println(str1 + str2);//SeleniumTesting


System.out.println("Selenium" + "Testing");//SeleniumTesting




2) String Comparison

In Computer programming we have two types of comparison,

1) 2-way Comparison (true/false)
2) 3-way Comparison (0, Greater than 0, Less than 0)

Ways of String Comparison

a) String Comparison using Relational operator (==)
It supports 2-way Comparison

b) String Comparison using equals() method
It supports 2-way Comparison

c) String Comparison using compareTo() method
It supports 3-way Comparison

Result Criteria for 3 way comparison
if string1 = string2 then 0
if string1 > string2 then Positive value
if string1 < string2 then Negative value

Comparing 2 Numbers - based on their values (3 > 2)
Comparing 2 Strings - based on ANSI values

ANSI character codes

A to Z (65 to 90)
a to z (97 to 122)
0-9 (48 to 57)

Example:
String str1 ="SELENIUM";
String str2 = "selenium";
String str3="SELENIUM";
String str4="zabc";

//String Comparison using Relational (==) Operator
System.out.println(str1 == str2);//false
System.out.println(str1 == str3);//true

//String Comparison using equals() method



//String Comparison using compareTo() method
value

Value
}
}

3) Find String Length
String str ="SELENIUM";


String str ="SELENIUM";
int size = str.length();
System.out.println(size);