String interpolation allows you to insert the value of almost any valid boo expression inside a string by quoting the expression with ${}.
String interpolation kicks in for both [double] and triple quoted strings:
print("Now is ${date.Now}.") print("Tomorrow will be ${date.Now + 1d}") print(""" ---- Life, the Universe and Everything: ${len('answer to life the universe and everything')}. ---- """)
You can scape the $ character to prevent interpolation:
print("Now is \${date.Now}.") # outputs: Now is ${date.Now}.
You don't need to scape the $ char when it is not followed by the { character:
print("Calabresa R$ 4,50.")
Interpolation doesn't kick in inside [single quoted strings]:
print('Now is ${date.Now}.') # outputs: Now is ${date.Now}.
String Formatting
Boo also has the "%" (modulus) operator as shorthand for .NET/Mono's string.Format method. This is a little more similar to Python's string interpolation, too.
s = "Right now it is {0}. Say hi to {1}." print s % (date.Now, "Mary") //the above is basically shorthand for .NET's string.Format method: mystr = string.Format("x = {0}, y = {1}", x, y) //You can also pass the same parameters to Console.Write or WriteLine //if you just want to print out a formatted string: Console.WriteLine("x = {0}, y = {1}", x, y)
Combine boo and .net's string formatting
This tip suggested by Arron Washington. You can combine the two above techniques to get the best of both, like in this example:
first = "Reed" last = "H" age = 2 print "${first} ${last} is {0:00} years old." % (age,) //--> Reed H is 02 years old.
Another way is to pass formatting codes to the ToString method:
print age.ToString("00") //--> 02
