Weird behavior of awk

Question

Why do I get only "cat" when I run

awk 'BEGIN {
  animal[three] = "hen"
  animal[two]   = "dog"
  animal[one]   = "cat"
  for (var in animal) {
    print animal[var]
  }
}

??

Shouldn't it print "hen", "dog" and "cat"?

Missing a ' at the end of the code. – fedorqui Apr 10 '14 at 08:28 — fedorqui, Apr 10 '14 at 08:28

score 4 · Answer 1 · answered Apr 09 '14 at 11:07

Indices to awk arrays can either be numeric (as in a traditional array) or strings (an associative array). So you can either do

animal[1] = "cat"

or

animal["one"] = cat

However, if you do

animal[one] = cat

awk will try to find a variable called 'one', fail, and effectively do this:

animal[""] = cat

So in your program, all three animals are assigned to animal[""], so you end up with only one element in your array.

If you put one, two and three in quotes, your code will work as you expect.

Good one! You can also indicate by printing print animal[var], "-"var"-". var is empty, - to show where it starts and where it ends. — fedorqui, Apr 10 '14 at 08:29

1 Answers1