computer science tokens in c++ for school students

Tokens in c++

1. Name : R.Devipriya ReG. No : 1021719bd020 department: Computer science Class : XI

2. TOPIC ?

3. H ow do we construct C++ program?

4. TOPIC TOKENS IN C++

5. TOKENS Tokens are t h e basic building blocks in C++ language. T h e smallest individual units in a program are known as Tokens. A program is constructed using a combination of these tokens

6. C++ has following tokens

7. EXAMPLES: int , float, double, switch, break, c har, const, continue, default, for, if, static, void, sizeof , w h ile, return, long, do etc., KEYWORDS Definition: Sequence of characters t h at have fixed meaning. Keywords must be written in lower case Reserved identifiers and can’t be used as names for t h e 1) Program variables 2) user defined program elements

8. IDENTIFIERS It is the name given to a variable, function, array etc. These are the user defined names and consist of the sequence of the letters and digits with a letter as a first character .

9. EXAMPLES: Valid Identifiers Result   Test2   _sum   Power Invalid Identifiers Su-//  containing special character '-'.   2data    // the first letter is a digit.    break     // use of a keyword.     NAMING CONVENTION Only alphabetic characters, digits, and underscores are allowed. The identifier name cannot start with a digit or a number C++ identifiers are case-sensitive. A declared keyword cannot be used as a variable name.

10. Is t his a VALID IDENTIFIER? Num&add

11. Num&add is A INVALID IDENTIFIER REASON: special c h aracter except underescore is not permitted

12. CONSTANTS Definition: T h e Quantities w h ose value do not c h an g e during t h e program execution are known CONSTANTS

13. STRINGS Definition: A group of characters t h at are treated as a single item data enclosed in double quotes are known as STRINGS General Syntax : char string-name[size]; Size determines t h e number of c h aracters in t h e string name Example : char country[9]= “ INDIA”;

14. Is t his a VALID STRIN G ? ‘ WELCOME ’

15. ‘ WELCOME ’ is INVALID STRIN G REASON: Valid String should be enclosed within double quotes

16. PUNCTUATORS DEFINITION: Punctuators are symbols, which are used as delimiters, while constructing a C++ program. They are also called as  “Separators ”.

17. Operators DEFINITION: An operator is a symbol that tells the compiler to perform specific mathematical or logical manipulations. C++ is rich in built-in operators

18. Th a nk you