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- C++ Interfaces
How to define a variable in C++?
To define a variable in C++, you need to use the following syntax −
Syntax
datatype variable_name;
You need to know what type of data is your variable is going to hold and what it will be called. The variable name has constraints on what you can name it. Following are the rules for naming variables −
- Variable names in C++ can range from 1 to 255 characters.
- All variable names must begin with a letter of the alphabet or an underscore(_).
- After the first initial letter, variable names can also contain letters and numbers.
- Variable names are case sensitive.
- No spaces or special characters are allowed.
- You cannot use a C++ keyword (a reserved word) as a variable name.
Here are some examples of acceptable variable names −
mohd Piyush abc move_name a_123 myname50 _temp j a23b9 retVal
Examples of defining variables −
int my_var; float my_float; double num;
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