17 – Java Predefined Methods
Selenium Class 17 – Java Predefined Methods
Categories of Predefined Methods
i) String Methods
ii) Number Methods
iii) Character Methods
iv) Array Methods
Etc…
i) String Methods
1) compareTo() Method
It Compares two strings and supports 3-way comaprison
a) Result criteria for 2-way Comparison
if string1 == string2 then true
if string1 != string2 then false
b) Result criteria for 3-way Comparison
if string1 == string2 then 0
if string1 > string2 then Positive Value
if string1 < string2 then Negative Value
Comparing two numbers – based on their values
Comparing two strings – based on ANSI charcter codes
A-Z (65 to 90)
a-z (97 to 122)
0 to 9 (48 to 57)
5 > 3 – true
“UFT” > “Selenium” – true
Example:
String str1= “selenium”;
String str2= “SELENIUM”;
String str3 = “seleniuma”;
String str4 = “selenium”;
System.out.println(str1.compareTo(str2));//Positive Values
System.out.println(str1.compareTo(str3));//Negative Value
System.out.println(str1.compareTo(str4));//0
2) equals() Method
It Compares two strings and supports 2-way comaprison
Example:
String str1= “selenium”;
String str2= “SELENIUM”;
String str3 = “selenium”;
System.out.println(str1.equals(str2));//false
System.out.println(str1.equals(str3));//true
3) Cocat() Method
It concat two strings
String str1= “Selenium”;
String str2= ” Testing”;
System.out.println(str1.concat(str2));//Selenium Testing
System.out.println(“Selenium”.concat(” Java”));//Selenium Java
4) charAt() Method
Returns a Character value by Index
Example:
String str1= “Selenium”;
System.out.println(str1.charAt(1));//e
System.out.println(str1.charAt(7));//m
5) equalsIngoneCase();
It compares two strings and ignores letters (Upper case or Lower case)
Example:
String str1 = “selenium”;
String str2 = “SELENIUM”;
String str3 = “UFT”;
System.out.println(str1.equalsIgnoreCase(str2));//true
System.out.println(str2.equalsIgnoreCase(str3));//false
6) toUpperCase() Method
It conversts values to Upper Case
Example:
String str1 = “selenium”;
String str2 = “SELENIUM”;
String str3 = “SELEnium”;
String str4 = “Selenium123”;
System.out.println(str1.toUpperCase()); //SELENIUM
System.out.println(str2.toUpperCase());//SELENIUM
System.out.println(str3.toUpperCase());//SELENIUM
System.out.println(str4.toUpperCase());//SELENIUM123
7) toLowerCase() Method
It converts values to lower case
Example:
String str1 = “selenium”;
String str2 = “SELENIUM”;
String str3 = “SELEnium”;
String str4 = “Selenium123”;
System.out.println(str1.toLowerCase()); //selenium
System.out.println(str2.toLowerCase());//selenium
System.out.println(str3.toLowerCase());//selenium
System.out.println(str4.toLowerCase());//selenium123
8) trim() Method
It removes spaces from both sides of a string
Example:
String str = ” Selenium “;
System.out.println(str);
System.out.println(str.trim());
9) substring() method
Returns part of a string based on index position/s
Example:
String str = “Welcome to Selenium Testing”;
System.out.println(str.substring(11));//Selenium Testing
System.out.println(str.substring(20));//Testing
System.out.println(str.substring(11, 19));//Selenium
System.out.println(str.substring(8, 10));//to
10) endsWith() Method
It checks if a string ends with specified suffix or not? And supports 2-way comparison (true/false)
Example:
String str = “Welcome to Selenium Testing”;
System.out.println(str.endsWith(“Selenium Testing”));//true
System.out.println(str.endsWith(“Testing”));//true
System.out.println(str.endsWith(“Selenium”));//false
11) length property
Returns length of a String
String str = “Selenium Testing”;
String str2 = “Selenium”;
System.out.println(str.length());//16
System.out.println(str2.length());//8
ii) Number Methods
1) compareTo() method
Integer Class wraps a value of primitive data type int ia an Object
Comparing two numbers in 3-way comparison
Number1 == Number2 then 0
Number1 > Number2 then 1
Number1 < Number2 then -1
Example:
int x=7;
Integer a=x;
//Making primitive Data Type x is an Integer Object using Integer Class…
System.out.println(a.compareTo(7));//0 System.out.println(a.compareTo(5));//1
System.out.println(a.compareTo(9));//-1
2) equals() Method
It compares two numbers and supports 2-way comparison
int x=7;
Integer a=x;
System.out.println(a.equals(7));//true
System.out.println(a.equals(6));//false
System.out.println(a.equals(9));//false
3) abs() Method
It Returns absolute value
double a = 10.234;
double b = 10.789;
double c= -20.345;
int d=100;
int e=-23;
System.out.println(Math.abs(a));//10.234
System.out.println(Math.abs(b));//10.789
System.out.println(Math.abs(c));//20.345
System.out.println(Math.abs(d));//100
System.out.println(Math.abs(e));//23
4) round () Method
It rounds a value to nearest Integer
example:
double a=10.456;
double b=10.897;
double c=-10.345;
System.out.println(Math.round(a));//10
System.out.println(Math.round(b));//11
System.out.println(Math.round(c));//-10
5) min() Method
It returns minimum value between two numbers
Example:
int a=5;
int b=7;
double c=10.234;
double d = 10.789;
System.out.println(Math.min(a, b));//5
System.out.println(Math.min(c, d));//10.234
System.out.println(Math.min(11, 17));//11
System.out.println(Math.min(109.34, 103.45));//103.45
6) max() method
It returns maximum value between two numbers
int a=5;
int b=7;
double c=10.234;
double d = 10.789;
System.out.println(Math.max(a, b));//7
System.out.println(Math.max(c, d));//10.789
System.out.println(Math.max(9, 7));//9
System.out.println(Math.max(109.34, 103.45));//109.34
7) Random Number
It generates a Random Number
Example:
System.out.println(Math.random());