[string] How to check if matching text is found in a string in Lua?

There are 2 options to find matching text; string.match or string.find.

Both of these perform a regex search on the string to find matches.


string.find()

string.find(subject string, pattern string, optional start position, optional plain flag)

Returns the startIndex & endIndex of the substring found.

The plain flag allows for the pattern to be ignored and intead be interpreted as a literal. Rather than (tiger) being interpreted as a regex capture group matching for tiger, it instead looks for (tiger) within a string.

Going the other way, if you want to regex match but still want literal special characters (such as .()[]+- etc.), you can escape them with a percentage; %(tiger%).

You will likely use this in combination with string.sub

Example

str = "This is some text containing the word tiger."
if string.find(str, "tiger") then
  print ("The word tiger was found.")
else
  print ("The word tiger was not found.")
end

string.match()

string.match(s, pattern, optional index)

Returns the capture groups found.

Example

str = "This is some text containing the word tiger."
if string.match(str, "tiger") then
  print ("The word tiger was found.")
else
  print ("The word tiger was not found.")
end

Examples related to string

How to split a string in two and store it in a field String method cannot be found in a main class method Kotlin - How to correctly concatenate a String Replacing a character from a certain index Remove quotes from String in Python Detect whether a Python string is a number or a letter How does String substring work in Swift How does String.Index work in Swift swift 3.0 Data to String? How to parse JSON string in Typescript

Examples related to lua

How do I append to a table in Lua List file using ls command in Linux with full path Check if a string isn't nil or empty in Lua Roblox Admin Command Script How to add a "sleep" or "wait" to my Lua Script? How to iterate through table in Lua? Not Equal to This OR That in Lua How to read data from a file in Lua Lua string to int How to check if matching text is found in a string in Lua?

Examples related to conditional

Pandas/Python: Set value of one column based on value in another column Run an Ansible task only when the variable contains a specific string (Excel) Conditional Formatting based on Adjacent Cell Value Laravel Checking If a Record Exists Multiple conditions in if statement shell script The condition has length > 1 and only the first element will be used Creating a new column based on if-elif-else condition How to conditional format based on multiple specific text in Excel Using SUMIFS with multiple AND OR conditions Replacing Numpy elements if condition is met

Examples related to string-matching

Filter multiple values on a string column in dplyr PowerShell and the -contains operator Check if string matches pattern How to check if matching text is found in a string in Lua? Check whether a string contains a substring Perl - If string contains text? How to search a specific value in all tables (PostgreSQL)? javascript regular expression to check for IP addresses Regular Expression Match to test for a valid year How do I check if a string contains a specific word?