Selenium Lesson 10: Java Loops and String Handling|Java for Selenium|G C Reddy|

Java Control Flow Statements, Java Conditional or Decision Making Statements, Java Loop Statements and Java Branching Statements.
Java Loop Statements, Java for loop, Java while loop, Java do while loop, Java Enhanced for loop, Java Branching Statements, Java break statement, Java continue statement and Java return Statement.
String Handling in Java, What is String?, Declaring Strings in Java, String Concatenation and String Comparison.
Java Language Elements for Selenium Testing, Java programming examples and Java Conditional statements to insert verification points in Selenium test cases.

[gcreddy]

Class Notes:
Selenium Class 10: Java Control Flow Statements Part-2

Java Control Flow Statements
ii) Loop statements...

1) for loop
2) while loop
3) do while loop
4) Enhanced for loop

1) for loop

Description: It repeats a block of statements for a specified number of times,

Syntax:

for (Stratvalue; EndValue; Increment / Decrement){
Statements


}

Print 1 to 10 Numbers
Example:
for (int i=1; i<=10; i++){
System.out.println(i);
}

Print 1 to 5 Numbers except 4th Number

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

if (i != 4){
System.out.println(i);
}

}

Print 1 to 10 Numbers in reverse Order

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

2) while loop

Description: It repeats a block of Statements while condition is true

Syntax:
initialization
while (condition){
Statements


Increment/Decrement
}

Examples:

i) Print 1 to 10 Numbers
ii) Print 10 to 1 Numbers
iii) Print 1 to 5 Numbers except 3rd number

int i=1;

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

int i=10;

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

int i=1;
while (i<=5){
if (i != 3){
System.out.println(i);
}
i++;
}

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){

}


iii) 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 class VariablesOperators {
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
}
}

//Or
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;
}

}


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
}
}