Web Development with ReasonML

Working with Strings

The last data type we’ll take up in this introduction is strings. Multi-character strings are enclosed in double quotes, and the ++ operator concatenates strings. Consider this statement:

let str = "door" ++ "bell"; /* binds value "doorbell" to variable str */

Back in the discussion of output for the program, we noted that code such as the example below doesn’t compile properly because ++ requires both its operands to be strings. The variable total is float, and the compiler will complain bitterly:

let total = float_of_int(qty) *. price;

let afterDiscount = total *. (1.0 -. discount);

Js.log("Price before discount: $" ++ total ++ ".");
Js.log("Price after discount: $" ...