1. String Methods

2. String message = " HELLO you! ";
Strings
String myString = "abcDEFMNopqrstYZ";
String message = " HELLO you! "; 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
'a'
'b'
'c'
'D'
'E'
'F'
'M'
'N'
'o'
'p'
'q'
'r'
's'
't'
'Y'
'Z' 1 2 3 4 5 6 7 8 9 10 11 12 13
' '
'H'
'E'
'L'
'O'
'y'
'o'
'u'
'!'

3. String Methods length() charAt(int index) toLowerCase() toUpperCase()
equals(String s)
equalsIgnoreCase(String s)
returns the length (number of characters) of a string
returns character at index position
converts the supplied String to lowercase
converts the supplied String to uppercase
compares 2 Strings – returns a boolean value (true/false)
compares 2 Strings (ignoring case) – returns a boolean value (true/false)

4. String Methods replace(char x, char y) trim() substring(int begin)
substring(int begin, int end)
concat(String s)
returns a new String with all occurrences of the character x replaced with the character y
returns a new String with all leading and trailing spaces removed
returns a new String starting at begin index to the end of the String
returns a new String starting at begin index to (end – 1) index (NB)
returns a new String with s appended to the end of the String

5. String Methods Printing out each character in a string individually:
String name = “Martin";
for (int index = 0; index < name.length(); index++)
System.out.print(name.charAt(index) + "\t");
System.out.println();
USEFUL: Checking if a character is uppercase (similar for lower case):
if (Character.isUpperCase(name.charAt(0))) {
System.out.println("'" + name.charAt(0) + "' is uppercase");
}//if
else {
System.out.println("'" + name.charAt(0) + "' is not uppercase");
}//else

6. String message = " HELLO you! ";
Strings
String myString = "abcDEFMNopqrstYZ";
String message = " HELLO you! "; 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
'a'
'b'
'c'
'D'
'E'
'F'
'M'
'N'
'o'
'p'
'q'
'r'
's'
't'
'Y'
'Z' 1 2 3 4 5 6 7 8 9 10 11 12 13
' '
'H'
'E'
'L'
'O'
'y'
'o'
'u'
'!'

7. String myString = ”abcDEFMNopqrstYZ"; String message = " HELLO you! ";
myString.length() myString.charAt(5) message.equals(" hello you! ") myString.toLowerCase() myString.toUpperCase() message.equalsIgnoreCase(" hello you! ") message.replace('L', '*') message.trim() message.substring(8) myString.substring(5,10) message.concat("!!!") myString.endsWith("stYZ") message.startsWith("HELLO") 16
'F'
false
"abcdefmnopqrstyz"
"ABCDEFMNOPQRSTYZ"
true
" HE**O you! "
"HELLO you!"
"you! "
"FMNop"
" HELLO you! !!!"

8. String myString = "abcDEFMNopqrstYZ"; String message = " HELLO you! ";
message.length() message.charAt(5) myString.equals(“abcDEFMNopqrstYZ") message.toLowerCase() message.toUpperCase() myString.equalsIgnoreCase(“ABCDEFMNOPQRSTYZ") myString.replace(‘Z', '*') myString.trim() myString.substring(8) message.substring(5,10) myString.concat("!!!") message.endsWith(“you!") myString.startsWith(“ HELLO") 14
‘L'
true
" hello you! ”
" HELLO YOU! "
" abcDEFMNopqrstY*"
"abcDEFMNopqrstYZ"
"opqrstYZ"
"LO yo"
"abcDEFMNopqrstYZ!!!"
false