### How can I find the index of the biggest element in an array?

 on Mar 08, 2001 at 08:03 UTC Need Help??
Contributed by Anonymous Monk on Mar 08, 2001 at 08:03 UTC
Q&A  > arrays

 Answer: How can I find the index of the biggest element in an array?contributed by GrandFather Given an array @data containing numeric data: ```my \$idxMax = 0; \$data[\$idxMax] > \$data[\$_] or \$idxMax = \$_ for 1 .. \$#data; [download]``` is not only compact but, somewhat surprisingly perhaps, comparable in speed to caching \$data[\$idxMax] as shown in most of the other variants. A cache variant is worth using if an expensive calculation is required in the comparison or a very large array is being processed. Answer: How can I find the index of the biggest element in an array?contributed by tye ```my \$index = 0; my \$maxval = \$myarray[ \$index ]; for my \$i ( 0 .. \$#myarray ) { \$maxval < \$myarray[\$i] and \$index = \$i if \$maxval < \$myarray[\$i]; } print "The greatest is element number \$index: \$myarray[\$index]\n"; [download]``` Answer: How can I find the index of the biggest element in an array?contributed by satchboost ```my \$index = 0; my \$maxval = \$myarray[ my \$index ]; for ( 0 .. \$#myarray ) { if ( \$maxval < \$myarray[\$_] ) { \$index = \$_; \$maxval = \$myarray[\$_]; } } print "Max is index \$index: \$myarray[\$index]\n"; [download]``` Answer: How can I find the index of the biggest element in an array?contributed by turnstep ```my \$max; my \$index; my \$x = 0; for ( @myarray ) { \$index = \$x and \$max = \$_ if !defined \$max or \$_ > \$max; \$x++; } print "The winner is element number \$index: \$myarray[\$index]\n"; [download]``` Answer: How can I find the index of the biggest element in an array?contributed by reisinge A one-liner where the array elements are the command line arguments: ```\$ perl -E 'say [ sort { \$ARGV[\$b] <=> \$ARGV[\$a] } 0..\$#ARGV ]->[0]' 42 + 1000 999 0 -1 [download]``` Answer: How can I find the index of the biggest element in an array?contributed by DillonYu Use mod:://List::Util's reduce: ```use List::Util qw /reduce/; my @arr= qw/7 6 4 90 5 7/; my \$index = reduce {\$arr[\$a] > \$arr[\$b] ? \$a : \$b} (0 .. \$#arr); print "\$index\n"; [download]``` Answer: How can I find the index of the biggest element in an array?contributed by salva and if what you need are the indexes for the \$n biggest elements: ```use Sort::Key::Top qw(nkeytop rnkeytop); my @data = ( 100, -2, 5, 12, 1, 1, 6786, ...); my @min_ix_n = nkeytop { @data[\$_] } \$n => 0..\$#data; my @max_ix_n = rnkeytop { @data[\$_] } \$n => 0..\$#data; [download]``` Answer: How can I find the index of the biggest element in an array?contributed by jdporter A recursive solution. ```sub _index_of_largest { my \$X = shift; my \$L = shift; my \$x = \$#_; my \$l = pop; defined \$X and \$L > \$l and (\$x,\$l) = (\$X,\$L); @_ or return \$x; unshift @_, \$x, \$l; goto &_index_of_largest } sub index_of_largest { @_ or die; _index_of_largest(undef,undef,@_); } my \$i = index_of_largest( @a ); [download]``` Answer: How can I find the index of the biggest element in an array?contributed by Skeeve ```my \$i = \$#data; my \$max = \$i; \$max = \$data[\$i] > \$data[\$max] ? \$i : \$max while \$i--; print "Max value is \$data[\$max], at index \$max\n" [download]```

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