main
The Operating system uses the value returned by
main method to determine whether the program succeeded or failed. A return value of 0 indicates success.
#include
This line is a preprocessor directive. Tell compiler that we need to use the
iostream library. The name inside angle brackets is a header. Every program that uses a library facility must include associated header. The directive
#include must be written on a single line, the
name of the header file and the
#include must appear on the same line. In general, #include directives should appear outside any function. Typically, all the #include directives for a program appear at the beginning of the file.
<<
Output operator takes two operands: the left-hand operand must be a ostream object; the right-hand operand is a to print. The operator writes its right-hand operand to the ostream that is its left-hand operand.
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