Perl Best Practices (excerpt)---06

The sixth chapter: Control structure 0 LU Ii.

Use the code block if, and do not use the suffix if.

For example, the following is not a good idea:

$sum + = $measurement if defined $measurement;

In fact, it equals:

if (defined $measurement) {

$sum + = $measurement;

} 0 on three continents.

The suffix if is to be persisted to the process Control statement. 0 Land establishments.

do not use unless, for, while, and until as suffixes. 0 Lu Wu.

Never use unless or until. 0 Land and land.

avoid C-style for statements. 0 Land Seven.

avoid indexing arrays or hashes within a loop. 0 Land Ba.

never mark an index more than once in a loop. 0 Lu Ying.

use a noun-method variable as a for loop iterator. 0 Qi 0.

always declare a for loop iterator with my. 0 Qi One.

to create a new list from the old list, use map instead of for. 0 Qi Ii.

to find the values in the list, use grep and first, not for. 0 Qi Three.

to convert the list, use for, not map. 0 Qi Restaurant.

use subroutine calls to separate complex list conversions. 0 Qi Wu.

never modify $_ in a list function. 0 Qi Lu.

avoid cascading if. 0 Qi Qi.

the use of table lookups is preferred when cascading equality tests. 0 qi Ba.

A ternary expression that uses a tabular format when a value is generated. 0 Qi Jiu.

do not use do...while loops. 0 BA 0.

reject loop iterations as much as possible and as early as you can. 0 ba.

do not distort the loop structure for the sake of concentration control. 0 ba.

use for and redo, do not use the irregular count while. 0 ba three.

label Each loop that will explicitly leave,

The label is then used for each next, last, and redo.

Perl Best Practices (excerpt)---06