Don't re-invent the wheel. Use the "sort" command like this: 
$ cat junk.txt
AGCT:0:370:1
AGGT:3:52:1
TGAA:2:233:0
AGAG:0:32:0
$ sort -t: -k2,3 junk.txt
AGAG:0:32:0
AGCT:0:370:1
TGAA:2:233:0
AGGT:3:52:1

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In reply to Re: Sort a 2D array based on 2 columns by Anonymous Monk
in thread Sort a 2D array based on 2 columns by masala_curry

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