The Ring programming language version 1.5.3 book - Part 33 of 184

1. Ring Documentation, Release 1.5.3
methods(object) --> Returns a list contains the object methods
Example:
o1 = new test
aList = methods(o1)
for x in aList
cCode = "o1."+x+"()"
eval(cCode)
next
Class Test
func f1
see "hello from f1" + nl
func f2
see "hello from f2" + nl
func f3
see "hello from f3" + nl
func f4
see "hello from f4" + nl
Output:
hello from f1
hello from f2
hello from f3
hello from f4
41.20 isattribute() Function
We can test if the object contains an attribute or not using the isattribute() function
Syntax:
isattribute(object,cAttributeName) --> Returns True if the object contains the attribute
Example:
o1 = new point
see isattribute(o1,"x") + nl # print 1
see isattribute(o1,"t") + nl # print 0
see isattribute(o1,"y") + nl # print 1
see isattribute(o1,"z") + nl # print 1
class point x y z
41.21 isprivateattribute() Function
We can test if the object contains a private attribute or not using the isprivateattribute() function
Syntax:
41.20. isattribute() Function 295

2. Ring Documentation, Release 1.5.3
isprivateattribute(object,cAttributeName) --> Returns True if the object
contains the private attribute
Example:
o1 = new person
see isprivateattribute(o1,"name") + nl +
isprivateattribute(o1,"address") + nl +
isprivateattribute(o1,"phone") + nl +
isprivateattribute(o1,"job") + nl +
isprivateattribute(o1,"salary")
Class Person
name address phone
private
job salary
Output:
0
0
0
1
1
41.22 ismethod() Function
We can test if the object class contains a method or not using the ismethod() function
Syntax:
ismethod(object,cMethodName) --> Returns True if the object class contains the method
Example:
o1 = new point
see ismethod(o1,"print") + nl # print 1
mylist = []
mylist + new point
see ismethod(mylist[1],"print") + nl # print 1
class point x y z
func print
see x + nl + y + nl + z + nl
41.23 isprivatemethod() Function
We can test if the object class contains a private method or not using the isprivatemethod() function
Syntax:
41.22. ismethod() Function 296

3. Ring Documentation, Release 1.5.3
isprivatemethod(object,cMethodName) --> Returns True if the object class contains
the private method
Example:
o1 = new Test
see isprivatemethod(o1,"f1") + nl +
isprivatemethod(o1,"f2")
Class Test
func f1
see "message from f1()" + nl
private
func f2
see "message from f2()" + nl
Output:
0
1
41.24 addattribute() Function
We can add an attribute (or a group of attributes) to the object state (not the class) using the addattribute() function
Syntax:
AddAttribute(object,cAttributeName|aAttributesList)
Example(1):
see new point {x=10 y=20 z=30}
Class Point
AddAttribute(self,["x","y","z"])
Example(2):
o1 = new point
addattribute(o1,"x")
addattribute(o1,"y")
addattribute(o1,"z")
see o1 {x=10 y=20 z=30}
class point
Output:
x: 10.000000
y: 20.000000
z: 30.000000
41.25 addmethod() Function
We can add a method to the object class using the addmethod() function This method can be used with any object from
the same class.
41.24. addattribute() Function 297

4. Ring Documentation, Release 1.5.3
Syntax:
AddMethod(Object,cNewMethodName,cMethodName|AnonymousFunction)
Example:
o1 = new point { x=10 y=20 z=30 }
addmethod(o1,"print", func { see x + nl + y + nl + z + nl } )
o1.print()
Class point
x y z
Output:
10
20
30
Instead of using anonymous function to add new method to the class, we can use the function name
Example:
o1 = new point { x=10 y=20 z=30 }
myfunc = func { see x + nl + y + nl + z + nl }
addmethod(o1,"print", myfunc )
addmethod(o1,"display", myfunc )
addmethod(o1,"show", myfunc )
o1.print()
o1.display()
o1.show()
Class point
x y z
Output:
10
20
30
10
20
30
10
20
30
Since we add the method to the class, any object from that class can use this method
Example:
o1 = new point { x=10 y=20 z=30 }
o2 = new point { x=100 y=200 z=300 }
o3 = new point { x=50 y=150 z=250 }
addmethod(o1,"print", func { see x + nl + y + nl + z + nl } )
41.25. addmethod() Function 298

5. Ring Documentation, Release 1.5.3
o1.print()
o2.print()
o3.print()
Class point
x y z
Output:
10
20
30
100
200
300
50
150
250
41.26 getattribute() function
We can get the object attribute value using the getattribute() function
Syntax:
GetAttribute(oObject,cAttributeName) ---> Attribute Value
Example:
o1 = new point
see getattribute(o1,"name") + nl +
getattribute(o1,"x") + nl +
getattribute(o1,"y") + nl +
getattribute(o1,"z") + nl
Class Point
x=10 y=20 z=30
name = "3D-Point"
Output:
3D-Point
10
20
30
Example:
We can Find a Class List Member using GetAttribute() using a function findclass() The Find uses the member name,
rather than the column number
myList =
[new Company {position=3 name="Mahmoud" symbol="MHD"},
new Company {position=2 name="Bert" symbol="BRT"},
new Company {position=1 name="Ring" symbol="RNG"}
]
41.26. getattribute() function 299

6. Ring Documentation, Release 1.5.3
see myList
see nl +"=====================" + nl + nl
for i = 1 to len(myList)
see "Pos: "+ i +" | "+ myList[i].position +" | "+ myList[i].name +
" | "+ myList[i].symbol +" | "+ nl
next
See findclass(myList, "MHD", "symbol") +nl ### Specify Member class name
###---------------------------------------
func findclass classList, cValue, classMember
See nl + "FindClass: " +" "+ cValue + nl + nl
for i = 1 to len(classList)
result = getattribute( classList[i], classMember )
See "Result-Attr: " + i +" "+ result +nl
if result = cValue
j = i
ok
next
return j
###--------------------------------------
class company position name symbol
Output:
Pos: 1 | 3 | Mahmoud | MHD |
Pos: 2 | 2 | Bert | BRT |
Pos: 3 | 1 | Ring | RNG |
FindClass: MHD
Result-Attr: 1 MHD
Result-Attr: 2 BRT
Result-Attr: 3 RNG
1
41.27 setattribute() function
We can set the object attribute value using the setattribute() function
Syntax:
SetAttribute(oObject,cAttributeName,Value)
Example:
o1 = new person
setattribute(o1,"cName","Mahmoud")
41.27. setattribute() function 300

7. Ring Documentation, Release 1.5.3
setattribute(o1,"nSalary",1000000)
setattribute(o1,"aColors",["white","blue","yellow"])
see o1
see o1.aColors
Class Person
cName
nSalary
aColors
Output:
cname: Mahmoud
nsalary: 1000000.000000
acolors: List...
white
blue
yellow
41.28 mergemethods() Function
We can share methods between classes without inheritance using the MergeMethods() function
This function merge class methods to another class.
Syntax:
MergeMethods(cClassNameDestination,cClassNameSource)
Example:
mergemethods("count","share")
mergemethods("count2","share")
o1 = new count { test() }
o1 = new count2 { test() }
Class Share
func one
see "one" + nl
func two
see "two" + nl
func three
see "three" + nl
Class Display
Func printline
see copy("*",20) + nl
Class Count from Display
Func test
printline()
one()
two()
three()
printline()
41.28. mergemethods() Function 301

8. Ring Documentation, Release 1.5.3
Class Count2 from Display
Func test
three()
two()
one()
printline()
Output:
********************
one
two
three
********************
three
two
one
********************
41.29 packagename() Function
We can know the package name of the latest sucessful import command using the packagename() function
Syntax:
packagename() --> Returns the package name of the latest sucessful import
Example:
load "weblib.ring"
import System.web
see packagename() # system.web
41.29. packagename() Function 302

9. CHAPTER
FORTYTWO
STDLIB FUNCTIONS
In this chapter we are going to learn about functions in the stdlib.ring
Before using the functions in the library, We must load the library first
load "stdlib.ring"
42.1 puts() function
print the value then print new line (nl)
Syntax:
puts(expr)
Example:
Load "stdlib.ring"
Puts("Hello, World!")
42.2 print() function
print string - support n,t and r
Also we can use #{variable_name} to insert variables values.
Syntax:
print(string) ---> String
Example:
print("nHello, WorldnnHow are you? tt I'm fine!n")
x=10 y=20
print("nx value = #{x} , y value = #{y} n")
42.3 Print2Str() Function
Syntax:
303

10. Ring Documentation, Release 1.5.3
print2Str(string) ---> String
Example:
world = "World!"
mystring = print2str("Hello, #{world} nIn Year n#{2000+17} n")
see mystring + nl
Output:
Hello, World!
In Year
2017
42.4 getstring() function
Get input from the keyboard - return value as string
getstring() ---> string
42.5 getnumber() function
Get input from the keyboard - return value as number
getnumber() ---> number
42.6 apppath() function
Get the path of the application folder
Syntax:
AppPath() ---> The path as String
Example:
Load "stdlib.ring"
# Application Path
Puts("Test AppPath()")
See AppPath() + nl
42.7 justfilepath() function
Get the path of the file, remove the file name.
Syntax:
JustFilePath(cFile) ---> The path as String
42.4. getstring() function 304