Variables in C++ - Reading Assignment

C++ Programming
#364

java is identical to cobol basic and c + is identical to java is so easy, …

#365

1-> a variable is a named object
2-> a variable a named object that determened the region in memory where the value or other associated properties is stored
3-> that means the named object (variable) will be created and assigned a memory adress
4-> an l-value refers to an object that persists beyond a single expression. An r-value is a temporary value that does not persist beyond the expression that uses it.
5-> a uninitialized variable is a variable that has not been given a known value, uninitialized variable can lead to unexpected results
6-> Undefined behaviour is the result of executing te code whose behaviour is not wel defined

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#366

  1. What is a variable in C++?
    a named object of the memory

  2. What is the Definition of a variable?
    a declaration that creates the variable

  3. What is Instantiation of a variable?
    When the object is created and stored in the memory

  4. What is the difference between an l-value and an r-value?
    (I couldn’t find this in the article we were supposed to read so instead I went on google)
    I-Value is an object that can be identified in the memory

R-Value can not be identified in the memory

  1. What is an uninitialized variable and what kind of behavior can you expect from such a variable?
    A variable that has not been given a value yet

  2. What is undefined behavior?
    When you initiate code that was not well defined by the C++ language.

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#367
  1. Variables in C++ are named objects in the memory where they store different types of data.
  2. Special kind of declaration statement for example int x; // define a variable named x, of type int
  3. Instantiation of a variable means that an object will be created and assigned a memory address
  4. l-value refers to persistent object in the memory, whereas r-value is the value assigned to that object.
  5. A variable that has not been given a value. Using uninitialized variables can lead to unpredicted results
    6.Undefined behavior is the result of executing code whose behavior is not well defined by the C++ language.
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#368

  1. A named object is called a variable

  2. Variables are containers for storing data values

  3. When a program is run, the variable will be created and assigned a memory address.

  4. I-value is an expression that yields an object reference. It always has a defined region of storage, so you can take its address. Whereas an r-value does not necessarily have any storage associated with it. It is temporary.

  5. A variable that has not been given a known value. This will result in a undefined behavior because a value has not been assigned to the object.

6.Undefined behavior is the result of executing code whose behavior is not well defined by the C++ language

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#369
  1. A named object
  2. A variable is a named region of memory.
  3. Object is created and assigned a memory address
  4. lvalue is something that points to a specific memory location. On the other hand, a rvalue is something that doesn’t point anywhere
  5. A variable that has no memory location. We can expect anything except what we expected the variable value to be.
  6. The result of executing code whose behavior is not well defined by the programming language.
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#370

A variable is an object that can store a value.

A variable is a named object, which in turn is a memory location.

The variable is created and space is reserved in RAM.

An lvalue refers to a memory location, the rvalue can be the actual data stored at the memory location, or just any data without an adress. An lvalue can be explained as the holder for a rvalue.

A variable that is not initialized in memory. Its use can cause unexpected behavior as C++ does not assign the memory space anything when the memory is empty. This means it uses whatever rvalue already is in that location.

Using code that leads to undefined behavior results in unpredictable code. It can work, it can also fail in a number of different ways. It is best to strive to avoid undefined behavior.

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#371

1. What is a variable in C++?

A named object is called a variable. In C++ variable is used to store data in a memory location, which can be modified or used in the program during program execution.

2. What is the Definition of a variable?

Variables are the name of memory locations that are allocated by compilers, and the allocation is done based on the data type used for declaring the variable.

3. What is Instantiation of a variable?

Instantiation is a fancy word that means the object will be created and assigned a memory address. Variables must be instantiated before they can be used to store values.

4. What is the difference between an l-value and an r-value?

l-values (the only values allowed on the left side of an expression) are values that have a memory address. (variables is an example of l-values)
r-values (are allowed only on the right side of an expression) are values that are temporary in nature, don’t have a dedicated memory address and are discarded after the expression is evaluated.

5. What is an uninitialized variable and what kind of behavior can you expect from such a variable?

A variable that has not been given a value is called uninitialized.

6. What is undefined behavior?

The result of executing code whose behavior is not well defined by the language.

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#372

Same here, I´m searching the web & reading for answers.

#373

What is a variable in C++? An object that has a name.

What is Definition of a variable? We call Definition of a variable to any declaration statement used to create a variable.

Int x; // define variable named x, of type int

What is Instantiation of a variable? “It means the object will be created and given a memory address.” Instantiation is an object assigned to a memory address (instance of an object).

W hat is the difference between an l-value and an r-value? I-value is the identifier of a memory location and R-value is the value of an expression.

What is an uninitialized variable and what kind of behaviour can you expect from such a variable? A variable that is not initialized in the memory, this causes issues in C++

What is undefined behaviour? Executing code that is not well defined by C++ lang. Better to avoid these practices.

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#374

1 A variable is a name for an object.
2 In the definition you associate the name and type, preferably with a comment.
3 When the program is run, a RAM address vill be assigned to the variable. It will be instantiated.
4 L-value is a dynamic variable, you can read and assign value to this variable. R-value is a static, a constant. In “int a=5” a is the L-value that is assigned the R-value 5.
5 If a variable is not initialized the value of that variable is not reset, thus random in some way.
6 With random input, you may not anticipate the correct output, an uninitialized variable may cause undefined behavior.

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#375
  1. What is a variable in C++? Name given to a memory location
  2. What is the definition of a variable? Containers for storing data value
  3. What is Instantiation of a variable? Specifying an initial value to assign to it (i.e., before it is used at all); Instantiation is a fancy word that means the object will be created and assigned a memory address. Variables must be instantiated before they can be used to store values.
  4. What is the difference between an l-value and an r-value?
    an lvalue is an object reference and an rvalue is a value. The difference between lvalues and rvalues plays a role in the writing and understanding of expressions. … An lvalue always has a defined region of storage, so you can take its address. An rvalue is an expression that is not an lvalue.
  5. What is an uninitialized variable and what kind of behaviour can you expect from such a variable? An uninitialized variable is a variable that has not been given a value by the program . Using the value stored in an uninitialized variable will result in undefined behaviour.
  6. What is undefined behaviour? undefined behaviour (UB) is the result of executing a program whose behaviour is prescribed to be unpredictable, in the language specification to which the computer code adheres.
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#376

  1. What is a variable in C++?
    A named region of memory

  2. What is Definition of a variable?
    A region of storage that has a value and other associated properties

  3. What is Instantiation of a variable?
    The action that a variable being created and assigned a memory address.

  4. What is the difference between an l-value and an r-value?
    An l-value is an object reference and an r-value is a value.

  5. What is an uninitialized variable and what kind of behaviour can you expect from such a variable?
    A variable that has not been given a value. It will give unexpected or undefined results.

  6. What is undefined behaviour?
    A behavior that doesn’t exist or in not properly written in a way that compiler can understand.

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#377
  • What is a variable in C++?
    An object with a name
  • What is the Definition of a variable?
    Declaration statement to create a variable
  • What is Instantiation of a variable?
    The object is created and assigned in memory in runtime
  • What is the difference between an l-value and an r-value?
    I undertand that l -value is a variable that has an address on memory, r-value does not have an address on memory or does not have a location on memory.
  • What is an uninitialized variable and what kind of behavior can you expect from such a variable?
    A variable that is not initialized and you cannot know what happens because the memory will give it any value store there.
  • What is undefined behavior?
    When you execute the code who behavior is unpredictable
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#378

Q.) What is a variable in C++?
A.) A variable is a name given to a memory location. The value stored in a variable can be changed during program execution. A variable is only a name given to a memory location, all the operations done on the variable effects that memory location. In C++, all the variables must be declared before use.

Q.) What is Definition of a variable?
A.)In computer programming, a variable or scalar is a storage location (identified by a memory address) paired with an associated symbolic name, which contains some known or unknown quantity of information referred to as a value. The variable name is the usual way to reference the stored value, in addition to referring to the variable itself, depending on the context. This separation of name and content allows the name to be used independently of the exact information it represents. The identifier in computer source code can be bound to a value during run time, and the value of the variable may thus change during the course of program execution.

Q.)What is Instantiation of a variable?

A.) Instance variables are created when an object is instantiated, and are accessible to all the constructors, methods, or blocks in the class. Access modifiers can be given to the instance variable.

Q.) What is the difference between an l-value and an r-value?
A.) An l-value refers to an object that persists beyond a single expression. An r-value is a temporary value that does not persist beyond the expression that uses it.
Q.)What is an uninitialized variable and what kind of behaviour can you expect from such a variable?
A.)An uninitialized variable is a variable that has not been given a value by the program (generally through initialization or assignment). Using the value stored in an uninitialized variable will result in undefined behavior.

Q.)What is undefined behaviour?
A.) undefined behavior (UB) is the result of executing a program whose behavior is prescribed to be unpredictable, in the language specification to which the computer code adheres. This is different from unspecified behavior, In the C community, undefined behavior may be humorously referred to as “nasal demons”, after a comp.std.c post that explained undefined behavior as allowing the compiler to do anything it chooses, even “to make demons fly out of your nose”. :face_with_thermometer:

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#379

  1. What is a variable in C++?
    A variable in c++ is a named object.

  2. What is Definition of a variable?

The declaration of a variable

  1. What is Instantiation of a variable?

Allocation of ram for a variable.

  1. What is the difference between an l-value and an r-value?

I-value = has a persistent address.
r-value = doesn’t have a persistent address.

  1. What is an uninitialized variable and what kind of behaviour can you expect from such a variable?
    The uninitialized variable is in the memory but has no value assigned. Can cause errors.

  2. What is undefined behaviour?
    When code which was not well defined is executed.

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#380

Q1. What is a variable in C++?

A1. A variable is a named region of memory

Q2. What is the Definition of a variable?

A2. A named object is called a variable, and the name of the object is called an identifier

Q3. What is Instantiation of a variable?

A3. Instantiation means that the variable will be created and assigned a memory address

Q4. What is the difference between an l-value and an r-value?

A4. lvalue is something that points to a specific memory location whilst an rvalue is something that doesn’t point anywhere.
rvalues are temporary and short lived, whilst lvalues live a longer life since they exist as variables

Q5. What is an uninitialized variable and what kind of behavior can you expect from such a variable?

A5. An uninitialized variable is a variable that has not been given a value and an uninitialized variable will result in undefined behavior

Q6. What is undefined behavior?

A6. Undefined behavior (UB) is the result of executing a program whose behavior is prescribed to be unpredictable

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#381

A variable is a named region of memory. (object)

The definition is a special declaration statement. It can define what a variable is named and its type.

Instantiation is when a variable is created and assigned a memory address when the program is ran.

l-values have an address in memory where r-values do not.

An uninitialized variable is one that has not been given a known value. When the variables are assigned a place in memory they receive the value that is already in that place of memory. Using the value stored in an uninitialized variable will result in undefined behavior.

Undefined behavior is the result of executing code whose behavior is not well defined by the C++ language.

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#382

  1. What is a variable in C++?
    A variable is a named region of memory.

  2. What is the Definition of a variable?
    Its a named object with value and other associated properties.

  3. What is Instantiation of a variable?
    Instantiation means the object will be created and assigned a memory address.

  4. What is the difference between an l-value and an r-value?
    l-value refers to memory location which identifies an object.
    r-value refers to data value that is stored at some address in memory.

  5. What is an uninitialized variable and what kind of behavior can you expect from such a variable?
    A variable without any given value. It will have an undefined behavior.

  6. What is undefined behavior?
    When anything is allowed to happen in the program execution.

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#383

  1. A variable is a named object.

  2. Memory allocation for holding a value for an object.

  3. Instantiation of a variable is when an object is created and assigned a memory address.

  4. An I-value has an address assigned to it at all times while an r-value needs to have an address assigned to it persistently.

  5. An uninitialized variable has not been assigned an object with a value in memory. It can cause unexpected behavior.

  6. Undefined behavior is when code that is executed, does not behave as it was intended to. There might be bugs uncovered in more execution iterations of the code.

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