String Functions

You already know that sometimes char , int and double values and variable can be automatically converted to strings. But sometimes you need to convert them manually. For example, if you want to receive a concatenated string out of 2 integers, you cannot just use operator +, because this will be an operation between integers. You must convert them to strings first. You should use one of these functions to convert them manually using functions IntToString , CharToString and DoubleToString :

string sRes;

// the following statement will assign sRes "1+2.500000=3.5";

sRes = IntToString ( 1 ) +

CharToString ( '+' ) +

DoubleToString ( 2.5 ) +

"=3.5";

You can also see from this example that it is legal in C++ to carry over a sentence to the next line. You just need to terminate it with semicolon.

Sometimes you may also want to convert a string value to int or double . Please keep in mind that not every string can be converted. For example string "one" cannot be converted to int or double . While it may sound like a number, it is not. Only strings which look like a number inside double quotes, like "123" or "0.28" , can be converted. You suppose to use functions StringToInt and StringToDouble to do this:

int iInt = StringToInt ( "123" ); // assign 123 to iInt

double dDouble = StringToDouble ( "12.3" ); // assign 12.3 to dDouble

If there is no conversion possible, then these functions return zero.

There are a couple of other functions to work with strings. These are StrLen , UpperCase and LowerCase . You can probably guess what they do by their name and example below:

// assign 4 to iLen because string "test" has 4 characters in it

int iLen = StrLen ( "test" );

// assign "TEST" to sUpperCased

string sUpperCased = UpperCase ( "test" );

// assign "test" to sLowerCased

string sLowerCased = LowedCase ( "TEST" );