Check Data Type and Conversion

In this chapter we are going to learn about the functions that can be used for

  • Checking Data Type
  • Checking Character
  • Conversion

Check Data Type

The next functions can be used to check the data type

  • isstring()
  • isnumber()
  • islist()
  • type()
  • isnull()

IsString() Function

Using the IsString() function we can know if the value is a string or not

Syntax:

IsString(value) ---> 1 if the value is a string or 0 if not

Example:

see isstring(5) + nl +          # print 0
    isstring("hello") + nl      # print 1

IsNumber() Function

Using the IsNumber() function we can know if the value is a number or not

Syntax:

IsNumber(value) ---> 1 if the value is a number or 0 if not

Example:

see isnumber(5) + nl +          # print 1
    isnumber("hello") + nl      # print 0

IsList() Function

Using the IsList() function we can know if the value is a list or not

Syntax:

IsList(value) ---> 1 if the value is a list or 0 if not

Example:

see islist(5) + nl +            # print 0
    islist("hello") + nl +      # print 0
    islist([1,3,5])             # print 1

Type() Function

We can know the type of a value using the Type() Function.

Syntax:

Type(value) ---> The Type as String

Example:

see Type(5) + nl +          # print NUMBER
Type("hello") + nl +        # print STRING
Type([1,3,5])               # print LIST

IsNULL() Function

We can check the value to know if it’s null or not using the IsNULL() function

Syntax:

IsNULL(value) ---> 1 if the value is NULL or 0 if not

Example:

see isnull(5) + nl +        # print 0
isnull("hello") + nl +      # print 0
isnull([1,3,5]) + nl +      # print 0
isnull("") + nl +           # print 1
isnull("NULL")              # print 1

Check Character

The next functions can be used to check character

  • isalnum()
  • isalpha()
  • iscntrl()
  • isdigit()
  • isgraph()
  • islower()
  • isprint()
  • ispunct()
  • isspace()
  • isupper()
  • isxdigit()

IsAlNum() Function

We can test a character or a string using the IsAlNum() Function

Syntax:

IsAlNum(value) ---> 1 if the value is digit/letter or 0 if not

Example:

see isalnum("Hello") + nl +     # print 1
    isalnum("123456") + nl +    # print 1
    isalnum("ABCabc123") + nl + # print 1
    isalnum("How are you")      # print 0 because of spaces

IsAlpha() Function

We can test a character or a string using the IsAlpha() Function

Syntax:

IsAlpha(value) ---> 1 if the value is a letter or 0 if not

Example:

see isalpha("Hello") + nl +     # print 1
    isalpha("123456") + nl +    # print 0
    isalpha("ABCabc123") + nl + # print 0
    isalpha("How are you")      # print 0

IsCntrl() Function

We can test a character or a string using the IsCntrl() Function

Syntax:

IsCntrl(value) ---> 1 if the value is a control character (no printing position)
                    or 0 if not

Example:

See iscntrl("hello") + nl +     # print 0
    iscntrl(nl)                 # print 1

IsDigit() Function

We can test a character or a string using the IsDigit() Function

Syntax:

IsDigit(value) ---> 1 if the value is a digit or 0 if not

Example:

see isdigit("0123456789") + nl +        # print 1
    isdigit("0123a")                    # print 0

IsGraph() Function

We can test a character or a string using the IsGraph() Function

Syntax:

IsGraph(value) ---> 1 if the value can be printed (Except space) or 0 if not

Example:

see isgraph("abcdef") + nl +    # print 1
    isgraph("abc def")          # print 0

IsLower() Function

We can test a character or a string using the IsLower() Function

Syntax:

IsLower(value) ---> 1 if the value is lowercase letter or 0 if not

Example:

see islower("abcDEF") + nl +    # print 0
    islower("ghi")              # print 1

IsPrint() Function

We can test a character or a string using the IsPrint() Function

Syntax:

IsPrint(value) ---> 1 if the value occupies a printing position or 0 if not

Example:

see isprint("Hello") + nl +             # print 1
    isprint("Nice to see you") + nl +   # print 1
    isprint(nl)                         # print 0

IsPunct() Function

We can test a character or a string using the IsPunct() Function

Syntax:

IsPunct(value) ---> 1 if the value is a punctuation character or 0 if not

Example:

see ispunct("hello") + nl +     # print 0
    ispunct(",")                # print 1

IsSpace() Function

We can test a character or a string using the IsSpace() Function

Syntax:

IsSpace(value) ---> 1 if the value is a white-space or 0 if not

Example:

see isspace("   ") + nl +       # print 1
    isspace("test")             # print 0

IsUpper() Function

We can test a character or a string using the IsUpper() Function

Syntax:

IsUpper(value) ---> 1 if the value is an uppercase alphabetic letter or 0 if not

Example:

see isupper("welcome") + nl +    # print 0
    isupper("WELCOME")           # print 1

IsXdigit() Function

We can test a character or a string using the IsXdigit() Function

Syntax:

IsXdigit(value) ---> 1 if the value is a hexdecimal digit character or 0 if not

Example:

see isxdigit("0123456789abcdef") + nl +  # print 1
    isxdigit("123z")                     # print 0

Conversion

The next functions can be used for conversion

  • number()
  • string()
  • ascii()
  • char()
  • hex()
  • dec()
  • str2hex()
  • hex2str()

Number() Function

We can convert strings to numbers using the Number() function or the + operator.

Syntax:

Number(string) ---> Number
0 + string ---> Number

Example:

see number("5") + 5 + nl        # print 10
see 0 + "10" + 2                # print 12

String() Function

We can convert numbers to strings using the String() function or the + operator.

Syntax:

String(number) ---> String
"" + number ---> String

Example:

see string(5) + 5 + nl          # print 55
see "" + 10 + 2                 # print 102

Ascii() Function

We can get the ASCII code for a letter using the Ascii() function

Syntax:

Ascii(character) ---> ASCII Code

Example:

See ascii("m") + nl +   # print 109
    ascii("M")          # print 77

Char() Function

We can convert the ASCII code to character using the Char() function.

Syntax:

Char(ASCII Code) ---> character

Example:

See char(109) + nl +    # print m
    char(77)            # print M

Hex() Function

We can convert decimal to hexadecimal using the Hex() function.

Syntax:

Hex(decimal) ---> hexadecimal

Example:

See hex(10) + nl +      # print a
    hex(200)            # print c8

Dec() Function

We can convert hexadecimal to decimal using the Dec() function

Syntax:

Dec(hexadecimal) ---> decimal

Example:

See dec("a") + nl +     # print 10
    dec("c8")           # print 200

Str2hex() Function

We can convert string characters to hexadecimal characters using the Str2hex() function.

Syntax:

Str2hex(string) ---> hexadecimal string

Example:

See str2hex("hello")    # print 68656c6c6f

Hex2str() Function

We can convert hexadecimal characters to string using the Hex2str() function

Syntax:

Hex2Str(Hexadecimal string) ---> string

Example:

See hex2str("68656c6c6f")       # print hello