Script Languages Synopsis/if

if/unless control structure
Bash: if list; then list; [ elif list; then list; ] ... [ else list; ] fi

Perl:

if (expr) {block} [elsif (expr) {block}] [else {block}]

unless (expr) {block} [else {block}]

Ruby:

In Ruby, an if block is an expression, i. e., it returns the last evaluated value. The then keyword can be omitted, if a new line starts at this point.

if expr [then] expr... [elsif expr [then] expr...]... [else expr...] end

Example: points = if outcome=='gewonnen' then 3 elsif outcome=='unentschieden' then 1 else 0 end

Python:

if expr: block [ elif expr: block ] [ else: block ]

if modifier
Perl:

statement if expr

statement unless expr

Ruby:

expr if expr