String Handling | Computer for GCSE/IGCSE - Year 11 PDF Download

String Handling

• Strings are sequences of characters, encompassing letters, numbers, and symbols.
• They serve the purpose of representing textual information within a computer program.
• String handling encompasses the diverse operations applicable to strings.

Length

• The length of a string denotes the count of characters it encompasses.
• In Python, the len() function determines the length of a string.
• In Java, the length() method is employed to ascertain the length of a string.
• In Visual Basic, the Len() function is utilized to find the length of a string.

Substring

• A substring constitutes a segment of a string.
• In Python, slicing operator [:] extracts substrings.
• In Java, the substring() method retrieves substrings.
• In Visual Basic, the Mid() function is employed for obtaining substrings.

Upper

• The upper() method transforms all characters within a string into uppercase.
• In Python, upper() is utilized for this conversion.
• In Java, toUpperCase() is employed for converting a string to uppercase.
• In Visual Basic, the UCase() function serves the purpose of converting a string to uppercase.

Lower

• The lower() method changes all characters of a string to lowercase.
• In Python, lower() accomplishes this conversion.
• In Java, toLowerCase() is the method used to convert a string to lowercase.
• In Visual Basic, the LCase() function is employed to convert a string to lowercase.

Pseudocode example:
string phrase ← "EduRev"
length ← LENGTH(phrase)
substring ← SUBSTRING(phrase, 5, 2)
upper ← TO_UPPER(phrase)
lower ← TO_LOWER(phrase)

Python example:
phrase = "EduRev"
length = len(phrase)
substring = phrase[4:6]
upper = phrase.upper()
lower = phrase.lower()

Java example:
String phrase = "EduRev";
int length = phrase.length();
String substring = phrase.substring(4, 6);
String upper = phrase.toUpperCase();
String lower = phrase.toLowerCase();

Visual basic example:
Dim phrase As String = "EduRev"
Dim length As Integer = phrase.Length
Dim substring As String = phrase.Substring(4, 2)
Dim upper As String = phrase.ToUpper()
Dim lower As String = phrase.ToLower()

Position of First Character

• The indexing of the first character in a string can start at either position zero or one, depending on the programming language.
• In Python and Java, the first character of a string is located at position zero.
• Conversely, in Visual Basic, the first character of a string is positioned at index one.