PHP Fiber::start() Method: Usage and Examples

The PHP Fiber::start API performs a focused operation on an object or value. The examples below show its effect on actual data.

Starts execution of a Fiber, returning its first suspended value if it yields control.

What Is Fiber::start in PHP?

Starts execution of a Fiber, returning its first suspended value if it yields control.

Syntax:

Fiber::start(mixed $args = ...): mixed

The method accepts the following parameters:

• $args — Optional. The positional argument values passed to the callable.

Return type declared by PHP: mixed. The value or side effect is demonstrated in the examples below.

Example 1: Basic Usage

This example uses a small input to make the main behavior visible.

<?php

$fiber = new Fiber(function (): string {
    $input = Fiber::suspend("waiting");
    return "completed: " . $input;
});
echo $fiber->start();

Output:

waiting

Starts execution of a Fiber, returning its first suspended value if it yields control.

Example 2: A Different Input

A different set of values shows the same operation in another situation.

<?php

$fiber = new Fiber(function (): string {
    $input = Fiber::suspend("request");
    return "completed: " . $input;
});
echo $fiber->start();

Output:

request

A fiber must be suspended before resume() or throw(); getReturn() is available only after successful termination.

Practical Example: Applying the Feature

This example shows an application-style use of the feature, with its surrounding setup visible.

<?php

$fiber = new Fiber(function (): string {
    $input = Fiber::suspend("pending");
    return "completed: " . $input;
});
echo $fiber->start();

Output:

pending

The code is shown for learning. Adjust the class names, inputs and error handling to suit your application.

Important Behavior and Edge Cases

• A fiber must be suspended before resume() or throw(); getReturn() is available only after successful termination.
• Starts execution of a Fiber, returning its first suspended value if it yields control.
• Observe differences in empty inputs, invalid states and optional extension availability where relevant.

Comparison With Related Approaches

Common Beginner Mistakes

Key Takeaways

• Starts execution of a Fiber, returning its first suspended value if it yields control.
• A fiber must be suspended before resume() or throw(); getReturn() is available only after successful termination.
• Use the example that matches the values, runtime version and dependencies in your application.

Fiber::start is useful when its behavior matches the data structure and lifecycle of your PHP application. Choose it with a clear understanding of its preconditions and returned values.