What do you mean by String Constants in C++

Today i am happy and free to write so let's get on new topic say String constants. What are strings ? A string is nothing but the alphanumeric quantities. A String constant is a alphanumeric characters enclosed in double quotation marks whose maximum length is 255 chracters. Following are examples of a valid string constants.
1. "The result="
2. "Rs 2000.00"
3. " This is my program" etc
Some of invalid string constants are:
1. jonty -> chracters are not enclosed in double quotation marks.
2. "My name is %$% -> closing of double quotation marks are missing.
3. 'this is test' -> characters are not enclosed in quotation marks.
Now that should be enough for today do come back tomorrow more on the C++.....becoz quest never ends..........