If you look at output of this `awk` test, you see that `array` in `awk` seems to be printed at some random pattern. It seems to be in same order for same number of input. Why does it do so?

```
echo "one two three four five six" | awk '{for (i=1;i<=NF;i++) a[i]=$i} END {for (j in a) print j,a[j]}'
4 four
5 five
6 six
1 one
2 two
3 three

```

```
echo "P04637 1A1U 1AIE 1C26 1DT7 1GZH 1H26 1HS5 1JSP 1KZY 1MA3 1OLG 1OLH 1PES 1PET 1SAE 1SAF 1SAK 1SAL 1TSR 1TUP 1UOL 1XQH 1YC5 1YCQ" | awk '{for (i=1;i<=NF;i++) a[i]=$i} END {for (j in a) print j,a[j]}'
17 1SAF
4 1C26
18 1SAK
5 1DT7
19 1SAL
6 1GZH
7 1H26
8 1HS5
9 1JSP
10 1KZY
20 1TSR
11 1MA3
21 1TUP
12 1OLG
22 1UOL
13 1OLH
23 1XQH
14 1PES
1 P04637
24 1YC5
15 1PET
2 1A1U
25 1YCQ
16 1SAE
3 1AIE

```

Why does it do so, is there rule for this?