PHP array merging, inversion, de-weight, adding elements, etc.;

Parameter Default value
Function ABC ($a, $b, $c = 0) {
echo $a, $b, $c;
//}
ABC (1,3);
The result equals 130;

echo "<br>";

A vertical look at the code;
echo "<pre>";
function Def () {
$arr = Func_get_args ();
Var_dump ($arr);
//}
def (1,2,3,4,5);

Array definition
Two methods of definition
$arr 1 = [];
$arr 2 = array ();

Indexed array-
$arr 1 = [All-in-a-box, "ABC", and ";
Associative array, the last one without commas. One is key,1 is value;
$arr 2 = [
"One" = 1,
"Both" = 2,
"Three" = 3
//];
echo $arr 2["one"];

Array method
Bounce something out.
Array_pop ($arr 2);

add element, return index value
Array_push ($arr 2, "XYZ");


echo "<pre>";
Var_dump ($arr 2);
echo "<pre>";
Length
Count ($arr 2);
echo Count ($arr 2);

Determine if an array has a value
In_array ("1", $arr 2);
Var_dump (In_array ("1111", $arr 2));

Merging arrays
$arr 3 = Array_merge ($arr 1, $arr 2);
Var_dump ($arr 3);

Array inversion
$arr 4 = Array_reverse ($arr 2);
Var_dump ($arr 4);

Array de-weight
$arr 5 = Array_unique ($arr 1);
Var_dump ($arr 5);

To delete an element in an array
Unset ($arr 1[0]);
Var_dump ($arr 1);


Iterating through an array

$arr 1= [1,2,3,4,5,6,7];
$arr 2= [
 "One"=1,
 "Both"=2,
 "Three"=3,
 "Four"=4
];
For loop
for ($i = 0; $i < count ($arr 1); $i + +) {
Var_dump ($arr 1[$i]);
//}

The foreach traversal, where value is named, can be changed.
foreach ($arr 2 as $value) {
Var_dump ($value);
//}
Here the key and value are named, can be changed, and the corresponding changes can be made below.
foreach ($arr 2 as $key = = $value) {
Echo $key;
echo "-----";
Echo $value;
echo "<br>";
//}

Pointer traversal
echo "<pre>";
//var_dump (each ($arr 2));                

PHP array merging, inversion, de-weight, adding elements, etc.;