Salesforce Platform Developer Practice Exam

In Apex, what keyword is used to declare a constant variable?

1. final

2. static

3. const

4. constant

The correct answer is: final

In Apex, the keyword used to declare a constant variable is "final." When a variable is declared as final, it means that its value cannot be changed after it has been initialized. This is important in programming because it allows developers to create values that are consistent and reliable throughout the execution of their code. For example, using final for constant variables helps prevent accidental modifications that could lead to bugs or unexpected behavior. Declaring a variable as final ensures that any attempts to reassign it later in the code will result in a compile-time error. This promotes better code maintenance and readability, as other developers can quickly see that certain values are meant to remain constant and not be altered. The other keywords mentioned, such as static, const, and constant, do not serve the same purpose in Apex. Static, for example, is used to define a class-level variable that is shared among all instances of a class, but it does not imply immutability. The keywords const and constant are not used in Apex for variable declaration, which reinforces that final is the correct choice for declaring constants in this programming language.