sub array - Is it possible for a regex to identify all equal value subarrays? -

an equal value subarray subarray containing 1 or more consecutive elements of same value.

for example, lets our array is:

1,1,3

there 4 equal value sub-arrays:

[1], [1], [3], [1,1]

note elements can part of more 1 subarray.

i know [\d] matches digits, requirement failing me. asking regex solution out of curiosity.

there's no way 1 regex. in fact, recommend use more 1 version of string.

this regex should work:

^(\d+)(,\1){n} 

i've made adjustments ensure more robust regex:

• allows numbers greater 10
• will match @ start, ensuring count not thrown off

for array of length 4, should replace n 0, 1, 2, 3. means have match against 4 regexes.

(note n=0 same ^(\d+))

furthermore, have "behead" string, meaning first match against 1,1,1,3 (new example) , 1,1,3, , 1,3, , 3.

fun fact: can use regex behead string (group 1 have beheaded string):

^\d+,(.*) 

(obviously, need ensure you're not trying behead array of size 1.)

for array of size 4, need match against 4+3+2+1=10 regexes. should test see if regex matched; if did, know increment count 1. (note 10 maximum number of consecutive combinations array of 4.)

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here's explanation of why need use more 1 string. take regex:

(\d)(,?\1){n} 

again, n needs replaced. need use g modifier (or equivalent).

i'll use example of 1,1,1,1:

• n=0 gives 4 matches
• n=1 gives 2 matches
• n=2 gives 1 match
• n=3 gives 1 match

as can see, not handle overlapping matches well, because that's not how regex designed.