array_reduce reduces array into a single value. Basically, The array_reduce will go through every item with the result from last iteration and produce new value to the next iteration.
Usage: array_reduce ($array, function($carry, $item){...}, $defaul_value_of_first_carry)
Sum of array
$result = array_reduce([1, 2, 3, 4, 5], function($carry, $item){
return $carry + $item;
});result:15
The largest number in array
$result = array_reduce([10, 23, 211, 34, 25], function($carry, $item){
return $item > $carry ? $item : $carry;
});result:211
Is all item more than 100
$result = array_reduce([101, 230, 210, 341, 251], function($carry, $item){
return $carry && $item > 100;
}, true); //default value must set trueresult:true
Is any item less than 100
$result = array_reduce([101, 230, 21, 341, 251], function($carry, $item){
return $carry || $item < 100;
}, false);//default value must set falseresult:true
Like implode($array, $piece)
$result = array_reduce(["hello", "world", "PHP", "language"], function($carry, $item){
return !$carry ? $item : $carry . "-" . $item ;
});result:"hello-world-PHP-language"
if make a implode method, the source code will be :
function implode_method($array, $piece){
return array_reduce($array, function($carry, $item) use ($piece) {
return !$carry ? $item : ($carry . $piece . $item);
});
}
$result = implode_method(["hello", "world", "PHP", "language"], "-");result:"hello-world-PHP-language"