Questions

1. What's wrong with the following line of code? Correct it:

      name: John

2. Examine the system word in the console with ? system.
3. Give the values of i1 and i2 after evaluating i2: 1 + i1: 1.
4. To better see the difference between them, use print and probe on [10 * 5].
5. Coming from other languages, it is common to type the mistake to_float 42; what happens then? Explain this.

6. See whether you can find the results of the following expressions for yourself (see Chapter03/evaluation.red):

        print (6 < 13) and (42 < 33)
        print (43 < 42) xor (44 < 43)
        print complement 3

 

 

7. From the following code snippet evaluate the last three lines and explain the results:

        a: "red" ;== "red"
        b: copy a ;== "red"
        a = b
        a == b
        a =? b

8. What's the output of print [3 = 2 tab 5 = 5 tab 1 = 1.0]?
9. What is the output of on = (5 = 5)?
10. Look up the docs of now in the console and try out its refinements.
11. Why does square-root 9 + square-root 9 return 3.464101615137754 and not 6? Make it return 6.0.
12. Compile a minimal.red script with only a header. What is the size of the binary? Use –c and –r, is there a difference, and if so, why?