PHP deflate_init() Function: Usage and Examples

Creates a streaming compression context.

What Is deflate_init() in PHP?

Creates a streaming compression context.

Its syntax is:

deflate_init(int $encoding, array $options = []): DeflateContext|false

Parameters:

• $encoding — Accepted as int; required argument.
• $options — Accepted as array; optional default [].

Return type: DeflateContext|false. Choose the matching encoding when later decompressing. Contexts cannot be reused after finishing a stream.

Availability: Requires zlib.

Example 1: Basic Usage

<?php

$compressionContext = deflate_init(ZLIB_ENCODING_RAW); var_dump($compressionContext instanceof DeflateContext);

Output:

bool(true)

Choose the matching encoding when later decompressing. Contexts cannot be reused after finishing a stream.

Example 2: A Different Input

<?php

$compressionContext = deflate_init(ZLIB_ENCODING_GZIP); echo get_debug_type($compressionContext);

Output:

DeflateContext

Choose the matching encoding when later decompressing. Contexts cannot be reused after finishing a stream.

Practical Example: Applying It in a Program

<?php

$compressionContext = deflate_init(ZLIB_ENCODING_RAW); $chunk = deflate_add($compressionContext, "Data", ZLIB_FINISH); echo strlen($chunk) > 0 ? "Compressed" : "Empty";

Output:

Compressed

Choose the matching encoding when later decompressing. Contexts cannot be reused after finishing a stream.

Important Behavior and Edge Cases

• Key behavior: Choose the matching encoding when later decompressing. Contexts cannot be reused after finishing a stream.
• Environment: Requires zlib.

Comparison With Related Functions

Common Beginner Mistakes

Key Takeaways

• Creates a streaming compression context.
• Choose the matching encoding when later decompressing. Contexts cannot be reused after finishing a stream.
• Requires zlib.

Summary: Choose the matching encoding when later decompressing. Contexts cannot be reused after finishing a stream.