Ring/Lessons/Strings

Strings In this chapter we are going to learn about strings creation and manipulation. String Literals Syntax: cStr = "This is a string" cStr2 = 'Another string' cStr3 = :JustAnotherString cStr4 = `Yet "another" 'string' ! ` Get String Length We can get the string length (letters count inside a string) using the len() function Syntax: len(string) ---> string length Example: cStr = "How are you?" see cStr + nl see "String size : " + len(cStr) + nl Convert Letters Case Syntax: lower(string) ---> convert string letters to lower case upper(string) ---> convert string letters to UPPER case Example: cStr = "Welcome To The Ring Programming Language" see cStr + nl + upper(cStr) + nl + lower(cStr) Access String Letters We can access a letter inside a string by the letter index Syntax: string[index] ---> get string letter string[index] = letter # set string letter Example: # print user name letter by letter (each letter in new line) See "Hello, Enter your name : " give cName for x = 1 to len(cName) see nl + cName[x] next We can use for in to get string letters. Example: # print user name letter by letter (each letter in new line) See "Hello, Enter your name : " give cName for x in cName see nl + x next We can modify the string letters Example: # convert the first letter to UPPER case See "Enter your name : " give cName cName[1] = upper(cName[1]) see "Hello " + cName Left() Function We can get a specified number of characters from a string using the Left() function. The starting position is 1. Syntax: Left(string,count) Example: see left("Hello World!",5) # print Hello Right() Function We can get a specified number of characters from a string using the Right() function. The starting position is the last character on the right. Syntax: Right(string,count) Example: see Right("Hello World!",6) # print World! Trim() Function We can remove all leading and trailing spaces from a string using the Trim() function. Syntax: trim(string) Example: cMsg = " Welcome " see trim(cMsg) # print Welcome Copy() Function We can duplicate a string more than one time using the copy() function. Syntax: copy(string,count) ---> string replicqated count times Example see copy("***hello***",3) # print ***hello******hello******hello*** Lines() Function We can count the number of lines inside a string using the Lines() function. Syntax: lines(string) ---> Number of lines inside the string Example: cStr = "Hello How are you? are you fine?" see lines(cStr) # print 3 Substr() Function We can work on sub strings inside a string using the substr() function. Using Substr() we can Find substring Get substring from position to end Get Number of characters from position Transform Substring To Another Substring Find substring Syntax: substr(string,substring) ---> the starting position of substring in string Example: cStr = "Welcome to the Ring programming language" see substr(cStr,"Ring") # print 16 Get substring from position to end Syntax: substr(string,position) ---> Get substring starting from position to end Example: cStr = "Welcome to the Ring programming language" nPos = substr(cStr,"Ring") # nPos = 16 see substr(cStr,nPos) # print Ring programming language Get Number of Characters From Position Syntax: substr(string,position,count) ---> Get characters starting from position Example: cStr = "Welcome to the Ring programming language" nPos = substr(cStr,"Ring") # nPos = 16 see substr(cStr,nPos,4) # print Ring Transform Substring To Another Substring Syntax: substr(string,substring,newsubstring) ---> Transformed string (Match case) substr(string,substring,newsubstring,1) ---> Transformed string (Ignore case) Example: cStr = "Welcome to the New programming language" see substr(cStr,"New","Ring") + nl # print Welcome to the Ring programming language see substr(cStr,"new","Ring",1)+ nl # print Welcome to the Ring programming language strcmp() Function We can compare between two strings using the strcmp() function. Syntax: strcmp(cString1,cString2) ---> value = 0 if cString1 = cString2 value < 0 if cString1 < cString2 value > 0 if cString1 > cString2 Example: see strcmp("hello","hello") + nl + strcmp("bcd","abc") + nl Output: 0 -1 1 str2list() and list2str() Functions We can convert string lines to list items using the str2list() function. Also we can convert the list to a string using list2str() function. Syntax: str2list(string) ---> list contains the string lines list2str(list) ---> string contains the list items Example: /* output: ** Items : 4 ** Item : Hello ** Item : How are you ? ** Item : are you fine ? ** Item : ok ** list2Str result = Hello ** How are you ? ** are you fine ? ** ok ** Done */ mystr = "Hello How are you ? are you fine ? ok" mylist = str2list(mystr) see "Items : " + len(mylist) + nl for x in mylist see "Item : " + x + nl next newstr = list2str(mylist) see "list2Str result = " + newstr if mystr = newstr see nl + "Done" else see nl + "Error!" ok Ring programming language