awk reading 2 input files but not getting expected value

I'm reading 2 input files but not getting expected value.
I should get an alpha value on file_1_data[*] but not getting any.

Please help.

>cat test6.sh
awk '
FILENAME==ARGV[1] { file_1_data[$1]=$0; print "----- 1 Line " NR " -----" $1; next }
FILENAME==ARGV[2] { file_2_data[$1]=$0; print "----- 2 Line " NR " -----" $1; next }
END {
# do actual data processing here
print "----- Line " NR " -----"
print "----- file_1_data[1] " file_1_data[1]
print "----- file_1_data[2] " file_1_data[2]
print "----- file_1_data[3] " file_1_data[3]
print "----- file_1_data[4] " file_1_data[4]
print "----- file_1_data[5] " file_1_data[5]
print "----- file_1_data[6] " file_1_data[6]
print "----- file_1_data[7] " file_1_data[7]
print "----- file_1_data[8] " file_1_data[8]
print "----- file_1_data[9] " file_1_data[9]
print "----- file_1_data[10] " file_1_data[10]
print "----- file_2_data[1] " file_2_data[1]
print "----- file_2_data[2] " file_2_data[2]
print "----- file_2_data[3] " file_2_data[3]
print "----- file_2_data[4] " file_2_data[4]
print "----- file_2_data[5] " file_2_data[5]
print "----- file_2_data[6] " file_2_data[6]
print "----- file_2_data[7] " file_2_data[7]
print "----- file_2_data[8] " file_2_data[8]
print "----- file_2_data[9] " file_2_data[9]
print "----- file_2_data[10] " file_2_data[10]
print "\n"
}
' infile1 infile2

>cat infile1
A
B
C
D
E
F
G
H
I
J

>cat infile2
1
2
3
4
5
6
7
8
9
10

>./test6.sh
----- 1 Line 1 -----A
----- 1 Line 2 -----B
----- 1 Line 3 -----C
----- 1 Line 4 -----D
----- 1 Line 5 -----E
----- 1 Line 6 -----F
----- 1 Line 7 -----G
----- 1 Line 8 -----H
----- 1 Line 9 -----I
----- 1 Line 10 -----J
----- 2 Line 11 -----1
----- 2 Line 12 -----2
----- 2 Line 13 -----3
----- 2 Line 14 -----4
----- 2 Line 15 -----5
----- 2 Line 16 -----6
----- 2 Line 17 -----7
----- 2 Line 18 -----8
----- 2 Line 19 -----9
----- 2 Line 20 -----10
----- Line 20 -----
----- file_1_data[1]
----- file_1_data[2]
----- file_1_data[3]
----- file_1_data[4]
----- file_1_data[5]
----- file_1_data[6]
----- file_1_data[7]
----- file_1_data[8]
----- file_1_data[9]
----- file_1_data[10]
----- file_2_data[1] 1
----- file_2_data[2] 2
----- file_2_data[3] 3
----- file_2_data[4] 4
----- file_2_data[5] 5
----- file_2_data[6] 6
----- file_2_data[7] 7
----- file_2_data[8] 8
----- file_2_data[9] 9
----- file_2_data[10] 10

Change the index of the first array from numerical to associative and use Code Tags around any source listings you want to post.

awk '
FILENAME==ARGV[1] { file_1_data[$1]=$0; print "----- 1 Line " NR " -----" $1; next }
FILENAME==ARGV[2] { file_2_data[$1]=$0; print "----- 2 Line " NR " -----" $1; next }
END {
# do actual data processing here
print "----- Line " NR " -----"
for(i in file_1_data)
    print "----- file_1_data["i"] " file_1_data
for(j in file_1_data)
    print "----- file_2_data["j"] " file_2_data[j]
}
' infile1 infile2