Strings\contains()

predicate returns Closure returns bool pure

string → (string → bool)

At a glance — Bind a substring to look for; the returned Closure asks 'does this string contain it?'. Wraps str_contains().

Returns a function which can be used to check if a string contains a defined sub string. The created function can then reused over any string, or used as part of a Higher Order Function such as array_filter().

/**
  * @param string $find The value to look for.
  * @return Closure(string):bool
  */
 Strings\contains(string $find): Closure

Returned Closure

When Strings\contains() is called, it returns the following Closure which can be used like a regular function.

/**
  * @param string $source
  * @return bool
  * @psalm-pure
  */ 
$function(string $source): bool

Examples

Partial Application

This can be used to create a simple closure which can be used as a regular function.

// Create function to check if a string starts with 'foo'
$containsFoo = Strings\contains('foo');

// Called as a function.
$containsFoo('its foo'); // true
$containsFoo('its bar'); // false

// Used in a higher order function.
$array = array_filter(['its foo', 'its bar'], $containsFoo);
print_r($array); // ['its foo']

Curried

This can be called inline using currying.

Strings\contains('foo')('its foo'); // true
Strings\contains('foo')('its bar'); // false

Inlined with Higher Order Function

If you are not planning on reusing the Closure created, you can just call it inline with a higher order function as its callable.

$array = array_filter(['its foo', 'its bar'], Strings\contains('foo'));

// ['its foo']

Details

Group: Strings
Subgroup: String predicate
Core Functions: str_contains()
Since: 0.1.0
Source: