What is the String class in Apex?

It is the built-in Apex class for text values. It provides instance methods you call on a String variable, such as trim(), contains() and substring(), and static methods you call on the class, such as String.isBlank(), String.valueOf() and String.join().

Is Apex String comparison case-sensitive?

It depends on how you compare. In my test, 'ABC' == 'abc' returned true because the == operator ignores case for Strings, while 'ABC'.equals('abc') returned false. contains(), startsWith() and endsWith() are case-sensitive too; use equalsIgnoreCase() or containsIgnoreCase() when case should not matter.

How do I check if a String contains a value in Apex?

Use contains() for an exact, case-sensitive match, or containsIgnoreCase() to ignore case. indexOf() returns the position of the text, or -1 if it is not found.

Why does split('.') return an empty list in Apex?

Because split() takes a regular expression, and a dot means any character. Escape it as split('\\.') to split on a literal dot. The same applies to |, +, *, ?, $ and brackets.

What is the difference between isBlank() and isEmpty()?

String.isBlank() returns true for null, an empty String and a String that contains only spaces. String.isEmpty() returns false for a String of spaces, because spaces count as content. For user input, isBlank() is usually the right check.

Apex String Class Methods in Salesforce with Examples

The String class in Apex is Salesforce’s built-in class for working with text, with methods such as contains(), substring(), split(), replace() and trim(). Instance methods are called on a String variable (name.trim()), and static methods are called on the class itself (String.isBlank(name)).

I ran every method in this tutorial as anonymous Apex in a Salesforce Developer Edition org, including the cases that surprise people: == ignoring case, split('.') returning an empty list, and calling a method on a null String. The real output is shown below, grouped by the job you need to do.

This Tutorial Covers: