Matching of regular expression in string in Julia – match() and eachmatch() Methods

The match() is an inbuilt function in julia which is used to search for the first match of the given regular expression r in the specified string s and then returns a RegexMatch object containing the match or nothing if the match failed.

Syntax:
match(r::Regex, s::AbstractString, idx::Integer)

Parameters:

• r::Regex: Specified regular expression.
• s::AbstractString: Specified string.
• idx::Integer: It specifies the point from which the searching get started.

Returns: It returns a RegexMatch object containing the match or nothing if the match failed.

Example:

# Julia program to illustrate
# the use of match() method

# Getting a RegexMatch object containing
# the match or nothing if the match failed.
R = r"G(.)G"
println(match(R, "GFG"))
println(match(R, "Geeks"))
println(match(R, "gfgGfG"))
println(match(R, "GFG", 1))
println(match(R, "GFG", 2))

Output:

RegexMatch("GFG", 1="F")
nothing
RegexMatch("GfG", 1="f")
RegexMatch("GFG", 1="F")
nothing

eachmatch()

The eachmatch() is an inbuilt function in julia which is used to search for all the matches of the given regular expression r in the specified string s and then returns a iterator over the matches. If overlap is true, the matching sequences are allowed to overlap indices in the original string, otherwise they must be from distinct character ranges.

Syntax:
eachmatch(r::Regex, s::AbstractString; overlap::Bool)

Parameters:

• r::Regex: Specified regular expression.
• s::AbstractString: Specified string.
• overlap::Bool: Specified overlap boolean value.

Returns: It returns a iterator over the matches.

Example:

# Julia program to illustrate
# the use of eachmatch() method

# Getting a iterator over the matches
R = r"G(.)G"
println(eachmatch(R, "GFG"))
println(eachmatch(R, "GeeksforGeeks"))
println(eachmatch(R, "Geeks"))
println(eachmatch(R, "GFG", overlap = true))
println(collect(eachmatch(R, "GFGGfGGeekGeeks", overlap = true)))

Output: