RE0509

metacharacters relation to match:

*:0-multi

+:1-multi

?:0-1

{n},{n,m},{n,}:the number of matching

string switch

eg: pattern="lynn|coco"

src1="hello,my name is lynn"

result1="lynn"

src2="hello,my name is coco"

result2="coco"

ignore case

eg:pattern="(?i)Lynn"

src="hello,my name is lynn"

result="lynn"

multi-repeat-character

eg:pattern="n{2}"

src="hello,my name is lynn"

result="nn"

digital match

eg:pattern="\d+"

src="I am 24 years old but 18 years in school"

result="24","18"

eg:pattern="[0-9]+"

src="I am 24 years old but 18 years in school"

result="24","18"

optional character match

eg:pattern="colou?r"

src1="color"    result=color

src2="colour"  result=colour

RE0509