How do you write an if statement in C++?

C++ has the following conditional statements:

  1. Use if to specify a block of code to be executed, if a specified condition is true.
  2. Use else to specify a block of code to be executed, if the same condition is false.
  3. Use else if to specify a new condition to test, if the first condition is false.

What is if-else statement in C++ with example?

C++ if…else…else if statement If condition1 evaluates to true , the code block 1 is executed. If condition1 evaluates to false , then condition2 is evaluated. If condition2 is true , the code block 2 is executed. If condition2 is false , the code block 3 is executed.

What is file in C++ with example?

Files are used to store data in a storage device permanently. File handling provides a mechanism to store the output of a program in a file and to perform various operations on it. A stream is an abstraction that represents a device on which operations of input and output are performed.

What is the use of if statement with example?

The IF statement works by checking the expression to see whether a condition is met and returns a value based on the output obtained. For example, based on the criteria, it returns one predetermined value if the condition is found to be true and a different predefined value if the statement is found to be false.

What is the syntax of if else statement?

Syntax. If the Boolean expression evaluates to true, then the if block will be executed, otherwise, the else block will be executed. C programming language assumes any non-zero and non-null values as true, and if it is either zero or null, then it is assumed as false value.

What is the use of && in C++?

The && (logical AND) operator indicates whether both operands are true. If both operands have nonzero values, the result has the value 1 . Otherwise, the result has the value 0 . The type of the result is int .

What does == mean in C++?

== is an Equal To Operator in C and C++ only, It is Binary Operator which operates on two operands. == compares value of left and side expressions, return 1 if they are equal other will it will return 0.

How do you declare a file in C++?

To create a file, use either the ofstream or fstream class, and specify the name of the file. To write to the file, use the insertion operator ( << ).

How do you run a file in C++?

  1. use notepad++ to write the C++ source code.
  2. using command line change the directory/folder where the source code is saved(using notepad++)
  3. compile: g++ file_name.cpp -o file_name.exe.
  4. run the executable: file_name.exe.

What is auto && in C++?

auto&& , a lambda template parameter C++14 introduced a position in the language where auto (or auto& , auto const& or auto&& ) can occur: in lambdas. Those lambdas are then the equivalent of template member functions in function objects.