Cut the code

Goal

Fill in three functions that cut pieces out of the product code in Code: its first three bytes, its last character, and the code with its first and last bytes removed.

Example

For Code = "GO-7421":

Code = "GO-7421"
fmt.Println(Prefix())      // GO-
fmt.Println(LastChar())    // 1
fmt.Println(WithoutEnds()) // O-742

Prefix is positions 0, 1 and 2. LastChar is the byte at position len(Code)-1, turned into a string. WithoutEnds starts at position 1 and stops just before the last position.

Rules

• Edit cut.go. Each function has a // TODO comment and a return line you will change.
• Code is a variable outside the functions. The tests give it different values, so read Code each time the functions run.
• Use indexing and slicing (Code[...]) to cut the pieces. The codes are plain ASCII and always at least three bytes long.
• LastChar must return a string, not a number. Remember that indexing gives a byte, which prints as a number until you convert it.
• Do not change the line var Code string or the func lines. Do not add imports.

What you'll practice

Zero-based positions, len(s)-1 for the last position, and s[start:end] where the end is not included.

Run it

gonomicon fetch week-1/09-03-cut-the-code
cd 09-03-cut-the-code
gonomicon test
gonomicon submit

Hints

1. Positions start at 0, and s[start:end] stops just before end. The first three bytes are positions 0, 1 and 2.
2. Prefix is Code[:3]. The last position is len(Code)-1. Dropping the first and last byte means starting at 1 and ending at len(Code)-1.
3. Prefix: return Code[:3]. LastChar: return string(Code[len(Code)-1]). WithoutEnds: return Code[1 : len(Code)-1].