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Suppose you want to store the 10 numbers. The one choice is to create a 10 different variable but it is difficult when number of variable are increases. So the next solution that is more feasible is array. An array is the collection of various similar type elements stored in contiguous memory locations. All the array elements share the common name. To uniquely identify each element an index or subscript is associated with the element. so the array is also known as subscript variable . In the given figure arrangement of array elements are shown. The address of the first element is 100. If the given array is of type integer and integer occupies 2 bytes then the next element in the array has address 102,104 etc as given in the figure. How to access array elements using subscript operator it is also shown in the given figure. Array index always start with 0. To access array element subscript operator is used.[] is called subscript operator.a[0] read a of 0 or 0th element of a C...

What is identifier. A Name in Java program is called identifier, which can be used for identification purpose. It can be a class name, interface name, method name, label name, variable name etc. Example In the above example words marked with red underline are identifiers. As you can see there are 5 identifiers Test (Class Name) main (Method Name) String (Pre-defined Class Name) args (Variable Name) println(Method Name) Rules / Convention for Identifier Naming While defining Java identifier name, we have to follow some rules as listed below. Allowed characters in Java identifier are listed below.  A to Z (Uppercase letters) a to z (Lowercase letters) 0 to 9 (Digits) _ (Underscore) $ (Dollar sign) Example:  contact_number ( ✓ ) contact#   (✕) Identifier can't starts with digit. Example abc123 ( ✓ ) 123abc (✕) Java is a case sensitive language all variable listed below are different, but it is not a good pr...

What is Reserved Words. In every language some words are already reserved to represent some action or meaning. For example in English some reserve words are listed below. Apple Run Cat Dog Eat Similarly in Java there are some words which meaning is already reserved, such words are called reserved words / keywords. In Java, Only 53 words are reserved words. Difference between Keywords and Reserved Literals If reserve words represents some functionality, then called Keywords . If reserve words represents some value, the called Reserve Literals . Reserve Literals (3) true (boolean value) false (boolean value) null (Object reference value) Keywords (50) Used Keywords (48) Unused Keyword (2) Goto Const All 53 Reserved Words List Data types (8) byte short int long float double boolean char Flow Control (11) if else switch case default while for do break continue return Modifiers (11) public private pr...

Rules for Creating the variable name Variable name can contain Alphabets (A-Z/a-z), Digits (0-9) and Underscore( _ ). A variable name must start with alphabet or underscore. Spaces and special systems are not allowed. Reserved words are not allowed as a variable name. A variable name should be meaningful. Go is case sensitive language so age, Age, AGE all are treated as a different variable. Some correct variable names name father_name fatherName __AGE number1 car_modal_name is_verified intnum Some incorrect variable names father's_name father#name 2persons 0007 000Name int a#b Note There are two popular ways to create multi-word variables. player_name: Each word is separated by an underscore playerName: camel case, the first word is in small and from second word first letter of each word is capitalized. Variable Scope Scope is the range of places where a variable is allowed to be used is called variable scope.Variable Scope can ...

Pointer is called the soul of c. The importance of pointer can be understood by the fact that most of the device driver or embedded system program are created in c. Pointer makes the c most usable and flexible programming. Due to the availability of the pointer, it is possible to write a program such as a device driver. These programs are also known as the device driver. To understand the pointer we have to first understand the memory organization of any variable. The following figure shows the fact. Whenever a variable stored in memory it occupies some memory space and every memory space has a unique number associated with it known as an address. Every byte in member has a different address. If we create an integer variable and suppose it occupy 2 bytes in memory, then two addresses are associated with it but its first address is enough to access it. so the address of next bytes is less useful. To access the address of a variable & (Address of) operator is used. To understa...

Literals in Java int a = 5; In the above expression, a is a variable but 5 is literal. Literal can be of many types, we will discuss all types of literal one by one. Integral Literal Any integer constant is treated as integral literal. it can be written in 3 formats. int a = 10; (decimal format) int a = 010; (octal format, equivalent to 8) int a = 0x10; (hexadecimal format, equivalent to 16) Note: Octal constants can contain digits from 0 to 9. Hexadecimal constants can contains digits from 0 to 9 and a to f, where a to f can be uppercase or lowercase. Example - 1: int a = 10;    ( ✓ ) int a = 0678;    (✕) // Compile time error, number too large int a = 0777;   ( ✓ ) int a = 0xace;   ( ✓ ) int a = 0xBeer;    (✕) // Compile time error, number too large Example - 2: int a; a = 10 + 010 + 0x10; System.out.println(a); // 34, because 010 = 8 and 0x10 = 16 so 10 + 8 + 16 Important Notes We(pr...

Function is a group of statements which perfoms an specific task. We have used many functions such as printf(),scanf() and many more while developing a program. The purpose of a function can be understood by the example of printf(). Whenever you want to print anything on the output screen you use the printf() function. Actually to send the output on the screen is a difficult task and a program of multiple statements is need to write but fortunately, this is already done by Dennis Ritchie . So you can print anything by using a single line. Types of function In c various function are already created such as printf(),scanf(),sqrt(),pow() etc.These are known as predefined function or library function . C also provide the facility to create your own function. The functions created by the programmer are known as user defined function . Every function is followed by a pair of parenthesis(). While working with a function, some input needs to be supplied to the function. The input is g...

Introduction to decision making Sometimes we need to introduce a power in our program, that our program should automatically make the decision. For example:  if the temperature of the day is more than 20 degree then it's hot otherwise it's cool. To introduce this kind of power in our program, we use decision making statements as the list below... if-else statements nested if-else statements else-if ladder switch/case-control statement Let's create a program to check whether a number is even or odd. Program to check a number is even or odd in Go lang. package main import "fmt" func main() { var n int32 fmt.Print("Enter any number:") fmt.Scan(&n) if n % 2 == 0 { fmt.Println(n,"is even") } else { fmt.Println(n,"is odd") } } Output: Enter any number:55 55 is odd  Explanation: A number is even if it is divisible by 2 otherwise odd. So to che...

Data type defines a set of related values, describe the operations that can be done on them and define the way the stored in memory.  For example: Suppose you have a Car of VW Polo, but a car can be of any other company with some other basic and some advanced features. But if we called a name Car, then in your mind a picture is created that there is a vehicle with 4-wheels and steering. Each car has some features like the color, company, make, model etc. Types in programming work in a similar way, For example, "Hello World" is a string and every string have some length. Numbers Go Comes with different types to represent numbers, Numbers can be categorized into two broad categories... Integer The integer represents only those numbers which don't include any decimal places and can be of any positive and negative numbers. Example : {1, 3, -4, 11, 123, 534} all are integer numbers Go's integer type can be uint8, uint16, uint32, uint64, int8, int16, in...

What is Data type In Java every variable have some type.  For example in the code snippet below x should be int and b should be boolean type variable. x = 10; b = true; Similarly in Java every expression also have some type. For example in the following code snippet if a + b + c would result int type result because a, b and c are int type variables. int a, b, c, d; a = 1; b = 1; c = 1; d  = a + b + c; Strictly type checking  In Java, each type is strictly defined means byte have range from -128 to 127, so value out of from this range is not acceptable by byte type. Each assignment is strictly checked for type compatibility. Due to above two reason java is called strongly type checked language.   Primitive Data Types 8 Primitive Data types in Java Signed / Unsigned Data types Examples int a = 10;  ( ✓ ) int a = -10;  ( ✓ ) float x = -5.8;  ( ✓ ) char ch = -'a';  (✕) boolean b = -true;  (✕) bool...