To declare variables that cannot change once a value is assigned, the developer can use the final keyword, which means that the variable can only be assigned a value once, either when declaring the variable or inside a constructor1. For example:
Java
// Declare a final variable and assign its value when declaring
final Integer creditAmount = 1000;
// Declare a final variable and assign its value in the constructor
final Integer debtAmount;
public MyClass() {
debtAmount = 500;
}
AI-generated code. Review and use carefully. More info on FAQ.
The developer cannot use the static keyword to achieve the same effect, as static variables are not final by default. Static variables are used to store class-level information that is shared across all instances of the class, and they can be changed by any method in the class or by external classes2. For example:
Java
// Declare a static variable and assign its value in the class constructor static Integer creditAmount; public MyClass() { creditAmount = 1000;
}
// Declare a static variable and assign its value in a static initializer static Integer debtAmount; static { debtAmount = 500;
}
// Change the value of the static variables in a method
public void updateAmounts(Integer newCredit, Integer newDebt) {
creditAmount = newCredit;
debtAmount = newDebt;
}
AI-generated code. Review and use carefully. More info on FAQ.
References:
* Using the final Keyword | Apex Developer Guide | Salesforce Developers
* Using the static Keyword | Apex Developer Guide | Salesforce Developers