regex - Find a string after two other strings with something between them -

let's go example:

"blablabla. name john , i'm 21 years old. blablabla"

other example:

"blablabla. name john , i'm 21 years old. - hi i'm mary , i'm 22 years old."

basically, want match age of first person (here, 21, 23 or whatever). idea know i'll have sentence beginning "my name $name , i'm 21" can't afford know $name. gross idea select number after "my name "+something+" , i'm ".

how 1 regex, knowing can't use catch groups?

what have far:

    (?<=<my name )(.*)(?= years old) 

ideally work:

    (?<=<my name .* , i'm )(.*)(?= years old) 

... not! .* can't in ahead group apparently (which makes sense).

thank kindly.

/my name (\w+) , i'm (\d+) years old./ 

now first matched group name, second matched group age.

---

if reason don't want use groups, can match:

/(?<=my name )\w+(?= , i'm )/ 

for name and:

/(?<= , i'm )\d+(?= years old.)/ 

for age.

---

have noticed, lookbehinds variable length not allowed (at least in regex engines know of, not logically impossible). however, can use \k alternative:

/my name \w+ , i'm \k\d+(?= years old.)/