When would you use global and local variables with a function?

Global variables are declared outside any function, and they can be accessed (used) on any function in the program. Local variables are declared inside a function, and can be used only inside that function. It is possible to have local variables with the same name in different functions.

Why is it unsafe for a function to return a local variable by reference?

The return statement should not return a pointer that has the address of a local variable ( sum ) because, as soon as the function exits, all local variables are destroyed and your pointer will be pointing to someplace in the memory that you no longer own. Any use of a pointer with such a value is invalid.

Can we access local variable outside the function?

Local variables cannot be accessed outside the function declaration.

Which situation is an appropriate use of a local variable?

Use a local variable to read from the Login and Password string controls when a user logs in and to write empty strings to these controls when the user logs out.

Is it safe to return reference of a local variable?

It’s possible to return a reference from a function. But be careful if you try to do this: You do not want to return a reference to a local variable within a function — because when the function ends, the storage space for the local variables goes away. Not good! But you can return a reference to a global variable.

What happens if we return address of a local variable?

Once the function returns it does not exist anymore and hence you should not return the address of a local variable. In other words the lifetime of a is within the scope( { , } ) of the function and if you return a pointer to it what you have is a pointer pointing to some memory which is not valid.

When the variable declared outside to the function is called?

Correct option – B Global variableExplanation:-The variables that are declared outside all functions are called global variable.

Can I use local variable in another function Python?

4 Answers. area is a local variable in a function, that means that outside of that function, you can’t access it. You should read up on scoping and functions. The best solution here is to return values from your functions, and pass arguments into others.

How do you use a local variable outside a function in Python?

Use the object attribute syntax to access a variable outside of a function. In a function named func , use the syntax func. variable = value to store value in variable as an attribute of func . To access value outside of func , use func() to run func , then use the syntax function_name.

What is the difference between local and global variable in python?

A global variable is a variable that is accessible globally. A local variable is one that is only accessible to the current scope, such as temporary variables used in a single function definition.

What is a local variable in Python?

Local Variable: Since local variables are defined inside the function so variables with the same name can be used in different functions. The above example illustrates the use of a local variable. However, that a statement outside of the function can’t refer to the variable named petName without causing an error. That’s because it has local scope.

How to return a value from a local variable in JavaScript?

Function local variable lifetimes are local to that function. If you have to use a value held by a local variable inside a function to another function, you can return the value from function1 (). collect the return value in the caller function.

Why can’t I set a variable outside of a function?

Well, you can not do so explicitly because the scope and lifetime of local variables are limited to that function. But if you want the variable of a F outside as well, the simplest possible solution is to make it global.

Do I need static variables for a function to return values?

Based on the code you’ve shown, you don’t need static variables and you don’t need to access the value through the function itself. You’re just trying to figure out how to give the caller the value you calculated. Returning values is what returndoes. See this gistand let me know. – binki Jan 16 ’17 at 16:43 | Show 2more comments