PHP · Theory

Filters

Theory

328/352

Filters

Don’t start Filters with jargon. Start with a Filters dry-run. That is the whole point.

Filters order — meaning → one Filters step Dev can write from memory → one limit. Dumping ten features helps nobody.

Skip Filters and skipping the failure case for Filters shows up in a first job task.

Dev ships Filters in a first job task. That is the use case worth saying.

Don’t do this with Filters — skipping the failure case for Filters. Interviewers spot it in ten seconds.

After Filters, Dev should still remember skipping the failure case for Filters.

Close Filters with — “If I skip it, a Filters dry-run goes wrong like this: skipping the failure case for Filters.”

Exam tip

Board: a Filters dry-run. Dry-run Filters. Name the trap: skipping the failure case for Filters.

Example

<?php
// Filters
$scores = [80, 90, 70];
$avg = array_sum($scores) / count($scores);
echo "avg=" . number_format($avg, 1) . "\n";
foreach ($scores as $s) {
  if ($s >= 80) echo "high: $s\n";
}

Filters: scores array, print avg, then high marks. Say the output.

Short notes

DefFilters — Dev uses it for a Filters dry-run in a first job task.
RuleFilters → one Filters step Dev can write from memory.
RememberFilters + a .php page (a first job task).
UseFilters in a first job task (a Filters dry-run).
TrapFilters — skipping the failure case for Filters.
ExFilters → a Filters dry-run.

PHP · Theory

Filters

← All stacks

Theory

328/352

Filters

Don’t start Filters with jargon. Start with a Filters dry-run. That is the whole point.

Filters order — meaning → one Filters step Dev can write from memory → one limit. Dumping ten features helps nobody.

Skip Filters and skipping the failure case for Filters shows up in a first job task.

Dev ships Filters in a first job task. That is the use case worth saying.

Don’t do this with Filters — skipping the failure case for Filters. Interviewers spot it in ten seconds.

After Filters, Dev should still remember skipping the failure case for Filters.

Close Filters with — “If I skip it, a Filters dry-run goes wrong like this: skipping the failure case for Filters.”

Exam tip

Board: a Filters dry-run. Dry-run Filters. Name the trap: skipping the failure case for Filters.

Example

<?php
// Filters
$scores = [80, 90, 70];
$avg = array_sum($scores) / count($scores);
echo "avg=" . number_format($avg, 1) . "\n";
foreach ($scores as $s) {
  if ($s >= 80) echo "high: $s\n";
}

Filters: scores array, print avg, then high marks. Say the output.

Short notes

DefFilters — Dev uses it for a Filters dry-run in a first job task.
RuleFilters → one Filters step Dev can write from memory.
RememberFilters + a .php page (a first job task).
UseFilters in a first job task (a Filters dry-run).
TrapFilters — skipping the failure case for Filters.
ExFilters → a Filters dry-run.

Filters

Example

Short notes

Questions

Filters

Example

Short notes

Questions