The difference between a variable resistor and a rheostat is the same as the difference between six and half a dozen.
Actually, there is a third step, call definition. Declaration is a statement to the compiler of what type an identifier is, definition is the allocation of memory for that identifier, and initialization is the assignment of an initial value to that identifier. Usually, declaration and definition are done together, but you can also add initialization in that step if desired. int a; /* declaration and definition */ a = 1; /* initialization */ int a = 1; /* declaration, definition, and initialization */ For the case of seperate declaration and definition, consider the struct... struct _mystruct { int a; }; /*declaration */ struct _mystruct mystruct; /* definition */ struct _mystruct { int a; } mystruct; /*declaration and definition */ Note: To be more precise: struct _mystruct; /* struct declaration */ struct _mystruct { int a; }; /* struct definition */ typedef struct _mystruct MYTYPE; /* type definition */ extern struct _mystruct mystructvar; /* variable declaration */ struct _mystruct mystructvar; /* variable definition */ struct _mystruct mystructvar = {7} ; /* variable definition with initialization */ struct _mystruct { int a; } mystruct; /* struct definition and variable definition */ extern struct _mystruct { int a; } mystruct; /* struct definition and variable declaration */
Declaring a variable or function reserves an entry in a symbol table for that function or variable (entries in a symbol table eventually become memory addresses during linkage). Defining a variable or function actually specifies the value to be stored in the memory location specified and/or the code that should be compiled. Examples: Declaration: int foo(); // Declares a function. int bar; // Declares a variable. Definition: int foo() { printf("Hello World"); } bar = 5; Declaration and definition: int bar = 5;
The variable.
a literal is a constant value, the difference is a variable can change it's value.
The accessibility. The global one: almost everywhere in the code may reference to the global variable directly. The private variable, is private to the declaring module (class, method, assembly) only. Outside of that module has no access to it directly.
difference between fixed and variable inputs
There are two ways to declare varibles. 1. Locally 2. Globally When you declare a variable locally in any function that means it is only accessible by that function. When you declare a variable globally so it is accessible by all the functions in the program. Declaring variables with static keyword means you are setting its value null.
The difference between a variable resistor and a rheostat is the same as the difference between six and half a dozen.
The difference between a controlled variable and a variable is in their state. A controlled variable is something which is rigid and constant while a variable is liable to change and inconsistent.
A declaration introduces the existence of a variable by specifying its data type and name, such as "int a;". A definition, in addition to declaring the variable, also allocates memory for it, such as "int a = 5;".
In languages like C, declaring a variable "volatile" tells the compiler that it can't assume that the variable is only changed by the program code. If the variable is not declared volatile, sometimes the compiler can make certain optimizations since it can assume that it knows everything about how the variable will be used. When it is declared volatile, the variable may be changed by an external process (for example, it could be connected to an I/O device), so it must always be fetched from memory. For a better explanation, see the related links.
Actually, there is a third step, call definition. Declaration is a statement to the compiler of what type an identifier is, definition is the allocation of memory for that identifier, and initialization is the assignment of an initial value to that identifier. Usually, declaration and definition are done together, but you can also add initialization in that step if desired. int a; /* declaration and definition */ a = 1; /* initialization */ int a = 1; /* declaration, definition, and initialization */ For the case of seperate declaration and definition, consider the struct... struct _mystruct { int a; }; /*declaration */ struct _mystruct mystruct; /* definition */ struct _mystruct { int a; } mystruct; /*declaration and definition */ Note: To be more precise: struct _mystruct; /* struct declaration */ struct _mystruct { int a; }; /* struct definition */ typedef struct _mystruct MYTYPE; /* type definition */ extern struct _mystruct mystructvar; /* variable declaration */ struct _mystruct mystructvar; /* variable definition */ struct _mystruct mystructvar = {7} ; /* variable definition with initialization */ struct _mystruct { int a; } mystruct; /* struct definition and variable definition */ extern struct _mystruct { int a; } mystruct; /* struct definition and variable declaration */
difference between constant and static variables in java
The difference between these both is that the control is what stays the same in an experiment and the variable is what changes.
Declaration is basically defining data type and length and assignment is to assign the value. Below is the declaration -- var a integer /* this means we are declaring a variable a as integer data type */ a= 5 /* this is assignment,we are assigning 5 to variable a */
The variable.