Thread: Dominant number in array View Single Post
 12-01-2012, 11:47 PM PM User | #9 007julien Regular Coder   Join Date: May 2012 Location: France Posts: 174 Thanks: 0 Thanked 27 Times in 25 Posts An alert(arr.sort().join(',')) give the string 1,18,2,2,22,222,27,33,40,41,41,41,41,42,58 which is an alphanumeric sort (sort(function(a,b){return a-b}) will assume a numeric increasing sort). The \1+ after the first sub-pattern (,\d+) in the regular expression /(,\d+)(\1+)/g is a back-reference (1 for first sub-pattern) which allows to match all repeated set of one comma followed by one or more digits. Then the anonymous function is called only for the duplicated numbers Code: `function(a,b){var m;if (lgt<(m=a.length/b.length)) {lgt=m;nmb=b.substr(1)}}` The first argument a is the matched pattern (for example ,2,2 and b the first sub-pattern (the first curly bracket : ,2 in this case). The count of repetitions is also a.length/b.length, we do not use the replace function (See this page for further explanations) but define lgt (for lengthsQuotient) and nmb (for one «dominant» number). NB : Its easy to define lgt=1 and nmb=arr[0] (with a nmb=+b.substr(1) to store a number) to replace a «This number appaers 0 times» by a better «This number 1 appears 1 time» with an alert('This number '+nmb+' appears '+lgt+' time'+(1