Static variables are variables that belong to an overall class, not a particular object of a class. Think of a static variable to be like a global variable – its value is shared across your entire org. Any particular object’s properties or values are completely irrelevant when using static.
Full Answer
What is a static variable in Salesforce?
For example, if an Apex DML request causes a trigger to fire multiple times, the static variables persist across these trigger invocations. To store information that is shared across instances of a class, use a static variable.
What is a static Boolean variable?
Static variables are only static within the scope of the request. They’re not static across the server, or across the entire organization. Can any one explain what does it mean? If i take a scenario like below - I have a class XXwhich has one static boolean variable state.
When does a static variable'state'retain its value?
A static variable retains the value only during this execution context. To answer your question, the value of the variable 'state' will be retained and visible across all three classes named 'A', 'B' and 'C' only when these classes are instantiated in the same execution context.
How to create a class with Boolean variable with default value true?
you can create a class with a static Boolean variable with default value true. In the trigger, before executing your code keep a check that the variable is true or not. Once you check make the variable false. Recursion occurs when the same code is executed again and again.
What is a static boolean?
static Boolean FALSE − This is the Boolean object corresponding to the primitive value false. static Boolean TRUE − This is the Boolean object corresponding to the primitive value true. static Class
What are static variables in Salesforce?
Static variables are variables that belong to an overall class, not a particular object of a class. Think of a static variable to be like a global variable – its value is shared across your entire org. Any particular object's properties or values are completely irrelevant when using static.
What is boolean data type in Salesforce?
Every field within Salesforce has a defined data type....Different Salesforce Field Types Depending on the Data Types and their Transformation Data Types.Data TypeField TypesTransformation Data TypesBooleanCheckboxIntegerDoubleCurrency, formula, number, percent, and roll-up summaryDecimal3 more rows•Feb 1, 2022
What is meaning of static in Salesforce?
Static variables are those which can be used without instantiating a class.Instance variables are called by object while static are called by class.Static variables and methods are not included in view state for a vf page.
What is difference between static and non static in Salesforce?
Difference is that Static method can acces static variable and belongs to the class whereas Non Static method and variables can be accesed only the object of the class. Second Major difference is that Static variable can not be overridden.
What is the difference between static variable and dynamic variable?
Static variables (should) remain the same e.g. temperature of a water bath, k constant of a particular spring. Dynamic variables change as the experiment progresses e.g. air temperature and pressure, amount of natural light.
What is Boolean flag in Salesforce?
So in salesforce you can designate a flag as a checkbox. The value of the checkbox is a true or false, so it is considered as a boolean.
How do you create a Boolean data type field in Salesforce?
For creating a Boolean field in the contact object follow the below steps: Setup->customize->contacts-> Fields->click on New button->select radio option Checkbox ->click on next button->select Default Value->checked and follow the further steps. Did this answer your question?
How do you know if a Boolean is true in Apex?
For now in Apex I can do booleanVariable = booleanVariable == true; and then do the if (booleanVariable) check.
How does a static variable work?
Static Variables: When a variable is declared as static, then a single copy of the variable is created and shared among all objects at a class level. Static variables are, essentially, global variables. All instances of the class share the same static variable.
What is the difference between global and static variable?
The difference between a static variable and a global variable lies in their scope. A global variable can be accessed from anywhere inside the program while a static variable only has a block scope.
How do you trigger a static variable in Salesforce?
A Static variable is a variable which is initialized when the class is loaded. All the static variables in a class are initialized before the object is created for the class. It is only static within the scope of 'Apex Transaction'. A Single copy of 'static variable' is shared by all the instances of the same class.
What is static variable?
A static variable is static only within the scope of the Apex transaction. It’s not static across the server or the entire organization. The value of a static variable persists within the context of a single transaction and is reset across transaction boundaries.
What is static method?
These items are handled in the order in which they appear in the class. A static method is used as a utility method, and it never depends on the value of an instance member variable. Because a static method is only associated with a class, it can’t access the instance member variable values of its class.
What is instance member variable?
An instance member variable is declared inside a class, but not within a method. Instance methods usually use instance member variables to affect the behavior of the method. Suppose that you want to have a class that collects two-dimensional points and plots them on a graph.
Can a static variable be accessed through an instance?
A class static variable can’t be accessed through an instance of that class. If class MyClass has a static variable myStaticVariable, and myClassInstance is an instance of MyClass, myClassInstance.myStaticVariable is not a legal expression. The same is true for instance methods.
Do local variables have to be evaluated before class names?
Local variable names are evaluated before class names. If a local variable has the same name as a class, the local variable hides methods and variables on the class of the same name. For example, this method works if you comment out the String line.
Can Apex classes be static?
In Apex, you can have static methods, variables, and initialization code. However, Apex classes can’t be static. You can also have instance methods, member variables, and initialization code, which have no modifier, and local variables.
Can you use static methods in Java?
You can use static methods and variables only with outer classes. Inner classes have no static methods or variables. A static method or variable doesn’t require an instance of the class in order to run.
valueOf (stringToBoolean)
Converts the specified string to a Boolean value and returns true if the specified string value is true. Otherwise, returns false.
valueOf (fieldValue)
Converts the specified object to a Boolean value. Use this method to convert a history tracking field value or an object that represents a Boolean value.
How does static variable work?
How does Static variable and Static method works. Static variables are only static within the scope of the request. They’re not static across the server, or across the entire organization.
Is XX.state static?
Even though XX.state is static, it is not "server static" or "shared static.". Each transaction gets its exactly one instance of XX.state. This behavior differs from Tomcat and other server implementations that use "static" to mean "across all instances.".
Do static variables belong to a class?
Static variables do not belong to an instance of a class, they belong to the transaction's static memory area. In your first example, given: public class XX { public static boolean state = true; }. You could write this code: XX A = new XX (), B = new XX (), C = new XX (); But, you couldn't later call:
