Strings in Apex
A string in Apex is a sequence of characters used to represent text. Just like in C#, it’s widely used for storing and manipulating text data.
You declare a string variable using the String keyword.
Example: Creating a Simple String
apex
String myName = ‘Mubashira’;
System.debug(myName); // Output: Mubashira
Just like you have a name, every element in a program needs a name too.
That’s what identifiers are — names for your variables, classes, and methods.
Without names, you wouldn’t know how to call or use things in your program!
String Properties and Common Methods in ApexShape
1. Get Length of a String
Returns the number of characters in the string using .length()
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String myName = ‘Mubashira’;
Integer size = myName.length();
System.debug(size); // Output: 9
2. Concatenation
a. Using + operator
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String firstName = ‘Mubashira’;
String lastName = ‘Khan’;
System.debug(firstName + ‘ ‘ + lastName); // Output: Mubashira Khan
b. Using String.format() (similar to placeholder format)
apex
String firstName = ‘Mubashira’;
String lastName = ‘Khan’;
System.debug(String.format(‘{0} {1}’, new List<String>{firstName, lastName})); // Output: Mubashira Khan
3. Case Conversion
apex
String myName = ‘Mubashira’;
System.debug(myName.toUpperCase()); // Output: MUBASHIRA
System.debug(myName.toLowerCase()); // Output: mubashira
4. Substring
Apex
String myName = ‘Mubashira’;
// First 3 characters
System.debug(myName.substring(0, 3)); // Output: Mub
// Last 3 characters
System.debug(myName.substring(myName.length() – 3)); // Output: ira
5. Trim Whitespace
Apex
String nameWithSpaces = ‘ Mubashira Khan ‘;
System.debug(nameWithSpaces.trim()); // Output: Mubashira Khan
6. Contains, StartsWith, EndsWith
apex
String name = ‘Mubashira Khan’;
System.debug(name.contains(‘Mub’)); // Output: true
System.debug(name.startsWith(‘Mub’)); // Output: true
System.debug(name.endsWith(‘Khan’)); // Output: true
7. Equals
Apex
String name1 = ‘Mubashira’;
String name2 = ‘Mubashira’;
System.debug(name1.equals(name2)); // Output: true
8. Copy (Simply assign it to a new variable)
apex
String name = ‘Mubashira’;
String copyName = name;
System.debug(copyName); // Output: Mubashira
9. Replace
apex
String fullName = ‘Mubashira Khan’;
String newName = fullName.replace(‘Mubashira’, ‘Tuba’);
String replacedChar = fullName.replace(‘a’, ‘@’);
System.debug(newName); // Output: Tuba Khan
System.debug(replacedChar); // Output: Mub@shir@ Kh@n
10. Insert (using substring + concatenation)
Apex doesn’t have a built-in insert method, but you can simulate it:
Apex
String name = ‘Mubashira’;
String newName = name.substring(0, 9) + ‘ Khan’;
System.debug(newName); // Output: Mubashira Khan
11. Remove (using substring)
apex
String fullName = ‘Mubashira Khan’;
String shortened = fullName.substring(0, 9); // Removes after index 8
System.debug(shortened); // Output: Mubashira
Practice Tasks
1.Create a Simple String:
Declare myName = ‘YourName‘ and print it
2. Length:
Print the length of myName.
3. Concatenation:
• Use + to join firstName and lastName.
• Use String.format().
4. Case Conversion:
Convert myName to uppercase and lowercase.
5. Substring:
• Get first 3 characters.
• Get last 3 characters.
6. Trim:
Trim a string with leading/trailing spaces.
7. Contains / StartsWith / EndsWith:
• Check if name contains ‘Mub‘.
• Starts with ‘Mu’? Ends with ‘Khan’?
8. Equals:
Compare name1 and name2.
9. Copy:
Copy myName into another variable.
10. Replace:
• Replace your first name.
• Replace ‘a’ with ‘@’.
11. Insert:
Simulate inserting middle name into full name.
12. Remove:
Remove last name from full name.
