Checking for existence of an element in an array in awk

gistfile1.txt

c82a1446be6c:~ decostad$ echo "1,2,3"|awk -F, '{{split($0,arr,",")};if ("1" in arr){print "found it"}}'
found it
c82a1446be6c:~ decostad$ echo "1,2,3"|awk -F, '{{split($0,arr,",")};if ("2" in arr){print "found it"}}'
found it
c82a1446be6c:~ decostad$ echo "1,2,3"|awk -F, '{{split($0,arr,",")};if ("3" in arr){print "found it"}}'
found it
c82a1446be6c:~ decostad$ echo "1,2,3"|awk -F, '{{split($0,arr,",")};if ("4" in arr){print "found it"}}'

c82a1446be6c:~ decostad$ echo "1,2,3"|gawk --profile -F, '{{split($0,arr,",")};if ("4" in arr){print "found it"}}'
c82a1446be6c:~ decostad$ cat awkprof.out
	# gawk profile, created Tue Apr  7 17:53:14 2015

	# Rule(s)

     1  {
     1  	split($0, arr, ",")
     1  	if ("4" in arr) {
			print "found it"
		}
	}
	
c82a1446be6c:~ decostad$ echo "1,2,3"|gawk --profile  '{{split($0,arr,",")};if (!("4" in arr)){print "not there"}}'
not there

c82a1446be6c:~ decostad$ cat awkprof.out
	# gawk profile, created Tue Apr  7 17:57:22 2015

	# Rule(s)

     1  {
     1  	split($0, arr, ",")
     1  	if (! ("4" in arr)) { # 1
     1  		print "not there"
		}
	}