Interview question

What are common PHP coding practices that hurt performance, and how do you avoid them? कौन-सी common PHP coding practices performance को नुकसान पहुंचाती हैं?

Answer

Anti-pattern	Better approach
Queries inside loops	Batch fetch before the loop / eager loading
Loading entire large files into memory	Stream with fopen()/fgets() or generators
Using count() inside a loop condition repeatedly	Store count in a variable before the loop
Overusing regular expressions for simple checks	Use native string functions (str_contains, str_starts_with)

// Bad - recalculates count() every iteration
for ($i = 0; $i < count($items); $i++) { ... }

// Good
$total = count($items);
for ($i = 0; $i < $total; $i++) { ... }

// Bad - loads whole file
$data = file_get_contents('huge.csv');

// Good - streams line by line
$handle = fopen('huge.csv', 'r');
while (($line = fgets($handle)) !== false) {
    // process line
}
fclose($handle);

Anti-pattern	बेहतर तरीका
Loop के अंदर queries	Loop से पहले batch fetch करें
बड़ी files पूरी memory में load करना	fopen()/fgets() से stream करें
Loop condition में count() बार-बार	Count को variable में store करें

// खराब
for ($i = 0; $i < count($items); $i++) { ... }

// अच्छा
$total = count($items);
for ($i = 0; $i < $total; $i++) { ... }

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