Variables

To create a new variable, you just need to determine the variable name & value. The value will determine the variable type and you can change the value to switch between the types using the same variable name.

Syntax:

<Variable Name> = <Value>

Tip

The operator ‘=’ is used here as an Assignment operator and the same operator can be used in conditions, but for testing equality of expressions.

Note

The Variable will contains the real value (not a reference). This means that once you change the variable value, the old value will be removed from memory (even if the variable contains a list or object).

Dynamic Typing

Ring is a dynamic programming language that uses Dynamic Typing.

x = "Hello"             # x is a string
see x + nl
x = 5                   # x is a number (int)
see x + nl
x = 1.2                 # x is a number (double)
see x + nl
x = [1,2,3,4]           # x is a list
see x                   # print list items
x = date()              # x is a string contains date
see x + nl
x = time()              # x is a string contains time
see x + nl
x = true                # x is a number (logical value = 1)
see x + nl
x = false               # x is a number (logical value = 0)
see x + nl

Deep Copy

We can use the assignment operator ‘=’ to copy variables. We can do that to copy values like strings & numbers. Also, we can copy complete lists & objects. The assignment operator will do a complete duplication for us. This operation called Deep Copy

list = [1,2,3,"four","five"]
list2 = list
list = []
See list        # print the first list - no items to print
See "********" + nl
See list2       # print the second list - contains 5 items

Note

To copy lists/objects by reference, See the (Using References) chapter about the Ref() function

Implicit Conversion

The language can automatically convert between numbers and strings.

Rules:

<NUMBER> + <STRING> --> <NUMBER>
<STRING> + <NUMBER> --> <STRING>

Note

The same operator ‘+’ can be used as an arithmetic operator or for string concatenation.

Example:

x = 10                  # x is a number
y = "20"                # y is a string
sum = x + y             # sum is a number (y will be converted to a number)
Msg = "Sum = " + sum    # Msg is a string (sum will be converted to a string)
see Msg + nl