first, the basic problem
1. Write out the output of the following program
Copy Code code as follows:
?
$STR 1 = null;
$str 2 = false;
echo $str 1== $str 2? ' Equal ': ' Not equal ';
$str 3 = ';
$str 4 = 0;
Echo $str 3== $str 4? ' Equal ': ' Not equal ';
$str 5 = 0;
$str 6 = ' 0 ';
echo $str 5=== $str 6? ' Equal ': ' Not equal ';
?>
2. Write out the output of the following program
Copy Code code as follows:
?
$a 1 = null;
$a 2 = false;
$a 3 = 0;
$a 4 = ';
$a 5 = ' 0 ';
$a 6 = ' null ';
$a 7 = array ();
$a 8 = Array (array ());
echo empty ($a 1)? ' True ': ' false ';
echo Empty ($a 2)? ' True ': ' false ';
echo Empty ($a 3)? ' True ': ' false ';
echo Empty ($a 4)? ' True ': ' false ';
echo Empty ($a 5)? ' True ': ' false ';
echo Empty ($a 6)? ' True ': ' false ';
echo Empty ($a 7)? ' True ': ' false ';
echo empty ($a 8)? ' True ': ' false ';
?>
3. Write out the output of the following program
Copy Code code as follows:
?
$test = ' aaaaaa ';
$ABC = & $test;
Unset ($test);
Echo $abc;
?>
4. Write out the output of the following program
Copy Code code as follows:
$count = 5;
function get_count () {
static $count = 0;
return $count + +;
}
Echo $count;
+ + $count;
Echo get_count ();
Echo get_count ();
?>
5. Write out the output of the following program
Copy Code code as follows:
?
$GLOBALS [' var1 '] = 5;
$var 2 = 1;
function Get_value () {
Global $var 2;
$var 1 = 0;
return $var 2++;
}
Get_value ();
echo $var 1;
echo $var 2;
?>
6. Write out the output of the following program
Copy Code code as follows:
?
function Get_arr ($arr) {
unset ($arr [0]);
}
$arr 1 = Array (1, 2);
$arr 2 = Array (1, 2);
Get_arr (& $arr 1);
Get_arr ($arr 2);
echo Count ($arr 1);
echo Count ($arr 2);
?>
7. Get the extension of a file in more than five ways
Requirements: dir/upload.image.jpg, find. jpg or JPG,
It must be handled using PHP's own processing functions, which can be encapsulated into functions such as GET_EXT1 ($file _name), get_ext2 ($file _name), and cannot be significantly duplicated.
second, algorithm problem
1. Using PHP to describe the bubble sort and fast sort algorithm, an object can be an array
2. Use PHP to describe order lookup and binary lookup (also called binary lookup) algorithm, order lookup must consider efficiency, object can be an ordered array
3. Write a two-dimensional array of sorting algorithm functions, can have versatility, you can call PHP built-in functions
"With Answer" (The following answer is not necessarily the best, just a simple reference)
first, the basic problem
1. Equality Equality Unequal
2. True true to True true to true false
3. aaaaaa
4.5 0 1
5.5 2
6.1 2
7. Get the extension of a file in more than five ways
Copy Code code as follows:
function Get_ext1 ($file _name) {
Return STRRCHR ($file _name, '. ');
}
function get_ext2 ($file _name) {
Return substr ($file _name, Strrpos ($file _name, '. '));
}
function Get_ext3 ($file _name) {
Return Array_pop (Explode ('. ', $file _name));
}
function Get_ext4 ($file _name) {
$p = PathInfo ($file _name);
return $p [' extension '];
}
function Get_ext5 ($file _name) {
Return Strrev (substr (Strrev ($file _name), 0, Strpos (strrev ($file _name), '. '));
}
second, algorithm problem
1. Using PHP to describe the bubble sort and fast sort algorithm, an object can be an array
Copy Code code as follows:
Bubble sort (Array sort)
function Bubble_sort ($array)
{
$count = count ($array);
if ($count <= 0) return false;
for ($i =0; $i < $count; $i + +) {
for ($j = $count-1; $j > $i; $j-) {
if ($array [$j] < $array [$j-1]) {
$tmp = $array [$j];
$array [$j] = $array [$j-1];
$array [$j-1] = $tmp;
}
}
}
return $array;
}
Quick sort (Array sort)
function Quick_sort ($array) {
if (count ($array) <= 1) return $array;
$key = $array [0];
$left _arr = Array ();
$right _arr = Array ();
for ($i =1; $i <count ($array); $i + +) {
if ($array [$i] <= $key)
$left _arr[] = $array [$i];
Else
$right _arr[] = $array [$i];
}
$left _arr = Quick_sort ($left _arr);
$right _arr = Quick_sort ($right _arr);
Return Array_merge ($left _arr, Array ($key), $right _arr);
}
2. Use PHP to describe order lookup and binary lookup (also called binary lookup) algorithm, order lookup must consider efficiency, object can be
an ordered array
Copy Code code as follows:
Binary lookup (Find an element in an array)
function Bin_sch ($array, $low, $high, $k) {
if ($low <= $high) {
$mid = Intval (($low + $high)/2);
if ($array [$mid] = = $k) {
return $mid;
}elseif ($k < $array [$mid]) {
Return Bin_sch ($array, $low, $mid-1, $k);
}else{
Return Bin_sch ($array, $mid +1, $high, $k);
}
}
return-1;
}
Order lookup (Find an element in an array)
function Seq_sch ($array, $n, $k) {
$array [$n] = $k;
for ($i =0; $i < $n; $i + +) {
if ($array [$i]== $k) {
Break
}
}
if ($i < $n) {
return $i;
}else{
return-1;
}
}
3. Write a two-dimensional array of sorting algorithm functions, can have versatility, you can call PHP built-in functions
Copy Code code as follows:
Two-dimensional array sorting, $arr is data, $keys is the sort of health value, $order is the collation, 1 is ascending, 0 is descending
function Array_sort ($arr, $keys, $order =0) {
if (!is_array ($arr)) {
return false;
}
$keysvalue = Array ();
foreach ($arr as $key => $val) {
$keysvalue [$key] = $val [$keys];
}
if ($order = = 0) {
Asort ($keysvalue);
}else {
Arsort ($keysvalue);
}
Reset ($keysvalue);
foreach ($keysvalue as $key => $vals) {
$keysort [$key] = $key;
}
$new _array = Array ();
foreach ($keysort as $key => $val) {
$new _array[$key] = $arr [$val];
}
return $new _array;
}
