IDL Else - Python

As a programmer, you might already know about the 'else' statement in Python. It is a conditional statement that runs a block of code when the 'if' statement is not true. On the other hand, IDL (Interactive Data Language) also has an 'else' statement that serves the same purpose. In this article, we will explore the similarities and differences between the 'else' statements in Python and IDL.

Syntax

The first difference you will notice is in the syntax of the 'else' statement. In Python, the 'else' statement follows the 'if' statement and starts with the keyword 'else':

if condition:
    # code block to run if condition is true
else:
    # code block to run if condition is false

In IDL, the syntax is slightly different. The 'else' statement follows the 'if' statement and is enclosed in braces:

IF condition THEN BEGIN
    ; code block to run if condition is true
ENDIF ELSE BEGIN
    ; code block to run if condition is false
ENDIF

Behavior

The 'else' statement in both Python and IDL behaves in a similar manner. If the condition in the 'if' statement is true, the code block following it will execute. If the condition is false, the code block following the 'else' statement will execute.

Nested If-Else statements

Both Python and IDL allow for nested 'if-else' statements. In Python, this can be achieved by indenting the code blocks:

if condition1:
    # code block to run if condition1 is true
    if condition2:
        # code block to run if condition2 is true
    else:
        # code block to run if condition2 is false
else:
    # code block to run if condition1 is false

In IDL, you can nest 'if-else' statements using the 'ELSEIF' keyword:

IF condition1 THEN BEGIN
    ; code block to run if condition1 is true
    IF condition2 THEN BEGIN
        ; code block to run if condition2 is true
    ENDIF ELSE BEGIN
        ; code block to run if condition2 is false
    ENDELSE
ENDIF ELSE BEGIN
    ; code block to run if condition1 is false
ENDIF

Conclusion

In conclusion, the 'else' statement in both Python and IDL serves the same purpose - to execute a code block when the 'if' statement is false. Although their syntax is slightly different, their behavior is the same. As a programmer, you must understand both the 'if-else' statements in Python and IDL to write efficient code.