The List Class provides methods for manipulating list data in Ring. Key methods include Add() to add an item, Delete() to remove an item by index, Item() to access an item by index, FindInColumn() to search for an item in a list column, and Sort() to return a new sorted list. Lists can be concatenated using the + operator and initialized from arrays or other lists.

1. Ring Documentation, Release 1.3
38.34 isleapyear() function
Check whether a given year is a leap year in the Gregorian calendar.
Syntax:
Isleapyear(number) ---> True/False
Example:
Load "stdlib.ring"
Puts("Test Isleapyear()")
year = 2016
if Isleapyear(year) see "" + year + " is a leap year."
else see "" + year + " is not a leap year." ok
38.35 binarydigits() function
Compute the sequence of binary digits for a given non-negative integer.
Syntax:
binarydigits(number) ---> string
Example:
Load "stdlib.ring"
Puts("Test Binarydigits()")
b = 35
see "Binary digits of " + b + " = " + Binarydigits(b)
38.36 matrixmulti() function
Multiply two matrices together.
Syntax:
Matrixmulti(List,List) ---> List
Example:
Load "stdlib.ring"
# Multiply two matrices together.
Puts("Test Matrixmulti()")
A = [[1,2,3], [4,5,6], [7,8,9]]
B = [[1,0,0], [0,1,0], [0,0,1]]
see Matrixmulti(A, B)
38.37 matrixtrans() function
Transpose an arbitrarily sized rectangular Matrix.
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Syntax:
Matrixtrans(List) ---> List
Example:
Load "stdlib.ring"
# Transpose an arbitrarily sized rectangular Matrix.
Puts("Test Matrixtrans()")
matrix = [[78,19,30,12,36], [49,10,65,42,50], [30,93,24,78,10], [39,68,27,64,29]]
see Matrixtrans(matrix)
38.38 dayofweek() function
Return the day of the week of given date. (yyyy-mm-dd)
Syntax:
dayofweek(string) ---> string
Example:
Load "stdlib.ring"
# Return the day of the week of given date.
Puts("Test Dayofweek()")
date = "2016-04-24"
see "Data : " + date + " - Day : " + Dayofweek(date) + nl
38.39 permutation() function
Generates all permutations of n different numerals.
Syntax:
permutation(list)
Example:
Load "stdlib.ring"
# Generates all permutations of n different numerals
Puts("Test Permutation()")
list = [1, 2, 3, 4]
for perm = 1 to 24
for i = 1 to len(list)
see list[i] + " "
next
see nl
Permutation(list)
next
38.38. dayofweek() function 229

3. Ring Documentation, Release 1.3
38.40 readline() function
Read line from file
Syntax:
readline(fp) ---> string
Example:
Load "stdlib.ring"
# Read a file line by line.
Puts("Test Readline()")
fp = fopen("test.ring","r")
while not feof(fp)
See Readline(fp) end
fclose(fp)
38.41 substring() function
Return a position of a substring starting from a given position in a string.
Syntax:
Substring(str,substr,npos) ---> string
Example:
Load "stdlib.ring"
# Return a position of a substring starting from a given position in a string.
Puts("Test Substring()")
a = "abcxyzqweabc"
b = "abc"
i = 4
see substring(a,b,i)
38.42 changestring() function
Change substring from given position to a given position with another substring.
Syntax:
Changestring(cString, nPos1, nPos2, cSubstr) ---> cString
Example:
Load "stdlib.ring"
# Change substring from given position for given position with a substring.
Puts("Test Changestring()")
see Changestring("Rmasdg",2,5,"in") # Ring
38.40. readline() function 230

4. Ring Documentation, Release 1.3
38.43 sleep() function
Sleep for the given amount of time.
Syntax:
sleep(nSeconds)
Example:
Load "stdlib.ring"
Puts("Test Sleep()")
see "Wait 3 Seconds!"
Sleep(3)
see nl
38.44 ismainsourcefile() function
Check if the current file is the main source file
Syntax:
IsMainSourceFile() ---> True/False
Example:
Load "stdlib.ring"
if ismainsourcefile()
# code
ok
38.45 direxists() function
Check if directory exists
Syntax:
DirExists(String) ---> True/False
Example:
Load "stdlib.ring"
see "Check dir : b:ring "
puts( DirExists("b:ring") )
see "Check dir : C:ring "
Puts( DirExists("C:ring") )
38.46 makedir() function
Make Directory
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Syntax:
MakeDir(String)
Example:
Load "stdlib.ring"
# Create Directory
puts("create Directory : myfolder")
makedir("myfolder")
38.46. makedir() function 232

6. CHAPTER
THIRTYNINE
STDLIB CLASSES
In this chapter we are going to learn about the classes in the stdlib.ring
• StdBase Class
• String Class
• List Class
• Stack Class
• Queue Class
• HashTable Class
• Tree Class
• Math Class
• DateTime Class
• File Class
• System Class
• Debug Class
• DataType Class
• Conversion Class
• ODBC CLass
• MySQL Class
• SQLite Class
• Security Class
• Internet Class
39.1 StdBase Class
Attributes:
• vValue : Object Value
Methods:
233

7. Ring Documentation, Release 1.3
Method Description/Output
Init(x) Set vValue Attribute to x value
Print() Print vValue
PrintLn() Print vValue then New Line
Size() return number represent the size of vValue
Value() return vValue
Set(x) Call Init(x)
39.2 String Class
Parent Class : StdBase Class
Methods:
Method Description/Output
Init(String|Number|List)
Lower() New String - Lower case characters
Upper() New String - Upper case characters
Left(x) New String - contains x characters from the left
Right(x) New String - contains x characters from the right
Lines() Number - Lines count
Trim() New String - Remove Spaces
Copy(x) New String - repeat string x times
strcmp(cString) Compare string with cString
tolist() List (String Lines to String Items)
tofile(cFileName) Write string to file
mid(nPos1,nPos2) New String - from nPos1 to nPos2
getfrom(nPos1) New String - from nPos1 to the end of the string
replace(cStr1,cStr2,lCase) New String - Replace cStr1 with cStr2 , lCase (True=Math Case)
split() List - Each Word as list item
startswith(substring) Return true if the start starts with a substring
endswith(substring) Return true if the start ends with a substring
Example:
Load "stdlib.ring"
See "Testing the String Class" + nl
oString = new string("Hello, World!")
oString.println()
oString.upper().println()
oString.lower().println()
oString.left(5).println()
oString.right(6).println()
oString = new string("Hi" + nl + "Hello" )
See oString.lines() + nl
oString = new string(" Welcome ")
oString.println()
oString.trim().println()
oString = new string("Hello! ")
oString.copy(3).println()
see oString.strcmp("Hello! ") + nl
see oString.strcmp("Hello ") + nl
see oString.strcmp("Hello!! ") + nl
oString = new string(["one","two","three"])
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oString.print()
see oString.lines() + nl
oString = new String(1234)
oString.println()
oString = new String("one"+nl+"two"+nl+"three")
aList = oString.tolist()
see "List Items" + nl See aList
oString = new String( "Welcome to the Ring programming language")
See "the - position : " + oString.pos("the") + nl
oString = oString.getfrom(oString.pos("Ring"))
oString.println()
oString.mid(1,4).println()
oString = oString.replace("Ring","***Ring***",true)
oString.println()
oString = oString.replace("ring","***Ring***",false)
oString.println()
oString1 = new string("First")
oString2 = new string("Second")
oString = oString1 + oString2
oString.println()
oString = oString1 * 3
oString.println()
for t in ostring see t next
oString.tofile("test.txt")
oString = new string("one two three")
see nl
see ostring.split()
oString {
set("Hello") println()
set("How are you?") println()
}
Output:
Testing the String Class
Hello, World!
HELLO, WORLD!
hello, world!
Hello
World!
2
Welcome
Welcome
Hello! Hello! Hello!
0
1
-1
one
two
three
4
1234
List Items
one
two
three
the - position : 12
Ring programming language
39.2. String Class 235

9. Ring Documentation, Release 1.3
Ring
***Ring*** programming language
******Ring****** programming language
FirstSecond
FirstFirstFirst
FirstFirstFirst
one
two
three
Hello
How are you?
39.3 List Class
Parent Class : StdBase Class
Methods:
Method Description/Output
Init(String|List)
Add(Value) Add item to the list
Delete(nIndex) Delete item from the list
Item(nIndex) Get item from the list
First() Get the first item in the list
Last() Get the last item in the list
Set(nIndex,Value) Set item value
FindInColumn(nCol,Value) Find item in a column
Sort() Sort items - return new list
Reverse() Reverse items - return new list
Insert(nIndex,Value) Inset Item after nIndex
example:
Load "stdlib.ring"
oList = new list ( [1,2,3] )
oList.Add(4)
oList.print()
see oList.item(1) + nl
oList.delete(4)
oList.print()
see oList.first() + nl
see oList.last() + nl
oList { set(1,"one") set(2,"two") set(3,"three") print() }
see oList.find("two") + nl
oList.sort().print()
oList.reverse().print()
oList.insert(2,"nice")
oList.print()
oList = new list ( [ [1,"one"],[2,"two"],[3,"three"] ] )
see copy("*",10) + nl
oList.print()
see "Search two : " + oList.findincolumn(2,"two") + nl
see "Search 1 : " + oList.findincolumn(1,1) + nl
oList = new list ( [ "Egypt" , "USA" , "KSA" ] )
for x in oList
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see x + nl
next
oList = new list ( [1,2,3,4] )
oList + [5,6,7]
oList.print()
oList = new list ( ["one","two"] )
oList2 = new list ( ["three","four"] )
oList + oList2
oList.print()
output:
1
2
3
4
1
1
2
3
1
3
one
two
three
2
one
three
two
three
two
one
one
two
nice
three
**********
1
one
2
two
3
three
Search two : 2
Search 1 : 1
Egypt
USA
KSA
1
2
3
4
5
6
7
one
two
three
39.3. List Class 237