String methods:
Uppercase: HELLO WORLD
Original: Hello world
Length: 11
Empty check: false
Empty string check: true

String substring:
First 5 chars: Hello
From index 6: world
Middle part: quick

String replace:
Replace 'world' with 'Dart': Hello Dart
Replace 'fox' with 'cat': The quick brown cat jumps over the lazy dog.

String trim:
Trimmed: "Hello world"
Original: "  Hello world  "

String contains:
Contains 'hello': false
Contains 'xyz': false

String split and join:
Split by space: Dart, | Flutter, | Programming
Words: 8 words

List methods:
Joined with commas: apple, banana, cherry, date
Joined with " - ": apple - banana - cherry - date
Joined numbers: 1 + 2 + 3 + 4 + 5
Single separator: apple|banana|cherry|date

List properties:
First item: apple
Last item: date  
Length: 4
Empty: false

Complex method chaining:
Uppercase first item: APPLE
Length of last item: 4
Substring of joined: apple bana
Replace in joined: orange, banana, cherry, date

Number operations:
First number: 1
Last number: 5
Count: 5