Friday's PHP quiz: some Brad programmer's adventures, one weird sequence and prizes

Rules of the game

Questions and answer choices

Question 1

<?php
$a = [1, 2, 3];
foreach($a as &$value) {}
foreach($a as $value) {}
print_r($a);

1. Array (1, 2, 3)
2. Array (1, 2, 2)
3. Array (3, 2, 1)
4. Mistake

Question 2

<?phpfunctionsowCrops(){ return'wheat'; }
functionmillWheat(){ return'flour'; }
functionbake($flour){ return'cupcake'; }
functiongenerator(){
    $flour = yield millWheat();
    $wheat = yield sowCrops();
    return bake($flour);
};
$gen = generator();
foreach ($gen as $key => $value) {
    echo $key . ' => ' . $value . PHP_EOL;
}
echo $gen->getReturn();

1. 0 => flour
    1 => wheat
   

   
   

2. 0 => wheat
    1 => flour
    2 => cupcake
   

   
   

3. 0 => flour
   1 => wheat
   cupcake 
   

   
   

4. cupcake

   
   

0 => flour
1 => wheat
cupcake 

Question 3

<?php 
print_r(...(new Foo()));

1. Yes, the Foo class must implement the Traversable interface.
2. Yes, the Foo class must implement the ArrayAccess interface methods.
3. No, there will be an error, the argument of the ...- operator must be an array

Question 4

1. non-recursive mergesort
2. heapsort (Edsger Dijkstra's smoothsort variation)
3. quicksort median of three
4. introsort

Question 5

<?phpclassFactory{
    publicfunctiongetLambda(): Closure{
        returnfunction(){
            printf("Here I am (%s)!\n", get_class($this));
        };
    }
    publicfunctiongetLambda2(): Closure{
        returnstaticfunction(){
            printf("Here I am (%s)!\n", get_class($this));
        };
    }
}

1. In one case, the keyword static :) is used, but it does not affect
2. The result of getLambda2 () cannot be bound to any object.
3. So you can not write: there will be a syntax error "Syntax error: static keyword used in wrong context"
4. The closure of getLamda2 () can bind (bindTo) only to classes

Question 6

<?php
$a = true;
$b = false;
$c = $a and $b;
$d = $a && $b;
var_dump($c);
var_dump($d);

1. bool(false)
   bool(false)
   

2. bool(false)
   bool(true)
   

3. bool(true)
   bool(true)
   

4. bool(true)
   bool(false)
   

bool(true)
bool(false)

Question 7

<?php
$a = 'a';
for ($i = 0; $i < 40; $i++) {
    echo $a++, PHP_EOL;
}

1. Figures from 0 to 39 will be displayed, as well as Warning: A non-numeric value encountered in at each iteration
2. Each iteration will display a '+'
3. Strange sequence:

   a
   b
   c
   d
   e
   f
   g
   h
   i
   j
   k
   l
   m
   n
   o
   p
   q
   r
   s
   t
   u
   v
   w
   x
   y
   z
   aa
   ab
   ac
   ad
   ae
   af
   ag
   ah
   ai
   aj
   ak
   al
   am
   an

a
b
c
d
e
f
g
h
i
j
k
l
m
n
o
p
q
r
s
t
u
v
w
x
y
z
aa
ab
ac
ad
ae
af
ag
ah
ai
aj
ak
al
am
an

Question 8

<?phpclassTestMe{
    publicfunctiontest(){
        if (0) {
            yield32332;
        }
        return [1,2,3];
    }
}
$t = new TestMe();
foreach ($t->test() as $id) {
    echo $id, PHP_EOL;
}
echo"The end", PHP_EOL;

1. 12332332
   The end
   

   
   

2. 123
   The end
   

   
   

3. The end
   

   
   

4. 32332
   The end
   

   
   

The end

Summarizing