how to merge some elements array in php? [closed] - php

Question

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Closed 10 years ago.
example:
Array (
[0] => 35
[1] => -
[2] => 59
[3] => *
[4] => 2
[5] => /
[6] => 27
[7] => *
[8] => 2 )
then calculated:
59*2=118
and the new array is:
Array (
[0] => 35
[1] => -
[2] => 118
[3] => /
[4] => 27
[5] => *
[6] => 2 )
this is my original source :
input ($_POST['numbers']) is a string, LIKE:
65*6/6+5-5
class calculator {
//property
private $str='';
private $len=0;
private $ar_str=array();
private $ar_design=array();
private $ar_sum=array();
private $ar_min=array();
private $ar_mult=array();
private $ar_divi=array();
//Method
public function __construct($str1=''){
$this->str=$str1;
$this->len=strlen($this->str);
$this->ar_str=str_split($this->str);
if($this->ar_str[0] == '+' ||
$this->ar_str[0] == '-' ||
$this->ar_str[0] == '*' ||
$this->ar_str[0] == '/' ||
$this->ar_str[$this->len-1] == '+' ||
$this->ar_str[$this->len-1] == '-' ||
$this->ar_str[$this->len-1] == '*' ||
$this->ar_str[$this->len-1] == '/'
){
exit("Syntax error!");
}else if(!filter_var($this->ar_str[0], FILTER_VALIDATE_INT)){
exit("just use numbers and 4 operators!");
}
$this->ar_design[0]=$this->ar_str[0];
//start for
$j=1;
for($i=1;$i<$this->len;$i++){
if($this->ar_str[$i] == '+' || $this->ar_str[$i] == '-' || $this->ar_str[$i] == '*' || $this->ar_str[$i] == '/'){
if($this->ar_str[$i-1] == '+' || $this->ar_str[$i-1] == '-' || $this->ar_str[$i-1] == '*' || $this->ar_str[$i-1] == '/'){
exit("Syntax error!");
}else{
$this->ar_design[$j]=$this->ar_str[$i];
$j++;
}
}else if(filter_var($this->ar_str[$i], FILTER_VALIDATE_INT)){
if($this->ar_str[$i-1] == '+' || $this->ar_str[$i-1] == '-' || $this->ar_str[$i-1] == '*' || $this->ar_str[$i-1] == '/'){
$this->ar_design[$j]=$this->ar_str[$i];
}else{
$j--;
$this->ar_design[$j]=$this->ar_design[$j].$this->ar_str[$i];
}
$j++;
}else{
exit("just use numbers and 4 operators!");
}
}//end of for
print_r($this->ar_design);//array this array should be calculate!!!!!
}//end construct
}
if(isset($_POST['numbers'])){
$num_str=trim($_POST['numbers']);
if($num_str!=''){
$num_str = str_replace('`','+',$num_str);
new calculator($num_str);
}
}
i could find the answer:
$this->len_d=count($this->ar_design);
$this->ar_cal[0]=$this->ar_design[0];
$k=1;
for($i=1;$i<$this->len_d;$i++){
if($this->ar_design[$i] == '*'){
$k--;
$this->ar_cal[$k]=$this->ar_design[$i-1]*$this->ar_design[$i+1];
$i++;
}else{
$this->ar_cal[$k]=$this->ar_design[$i];
}
$k++;
}
print_r($this->ar_cal);

Answer 1

You could do it with a loop and then executing it.
$array=Array (35,'-',59,'*',2,'/',27,'*',2);
foreach ($array as $value){
$stringify.=$value;
}
echo 'Calculation looks like this: '.$stringify.'<br/>';
function calculate( $math ){
$calc = create_function("", "return (" .$math. ");" );
return $calc();
}
echo calculate($stringify);
could be imroved, for example by validating the input...
Working example: http://allanthya.net/arrcalc2.php

Answer 2

<?php
$array = array( 35, '-', 59, '*', 2, '/', 27, '*', 2 );
print_r($array);
echo "<p>";
while ( true ) {
$div = array_keys($array, '/');
$mult = array_keys($array, '*');
$add = array_keys($array, '+');
$sub = array_keys($array, '-');
if ( count($div) >= 1 ) {
$index = $div[0];
$op1 = $array[$index-1];
$op2 = $array[$index+1];
$array[$index] = $op1 / $op2;
unset($array[$index-1]);
unset($array[$index+1]);
$array = array_values($array);
continue;
} else if ( count($mult) >= 1 ) {
$index = $mult[0];
$op1 = $array[$index-1];
$op2 = $array[$index+1];
$array[$index] = $op1 * $op2;
unset($array[$index-1]);
unset($array[$index+1]);
$array = array_values($array);
continue;
} else if ( count($add) >= 1 ) {
$index = $add[0];
$op1 = $array[$index-1];
$op2 = $array[$index+1];
$array[$index] = $op1 + $op2;
unset($array[$index-1]);
unset($array[$index+1]);
$array = array_values($array);
continue;
} else if ( count($sub) >= 1 ) {
$index = $sub[0];
$op1 = $array[$index-1];
$op2 = $array[$index+1];
$array[$index] = $op1 - $op2;
unset($array[$index-1]);
unset($array[$index+1]);
$array = array_values($array);
continue;
}
else {
break;
}
}
print_r($array);
echo "<p>";
?>
Heres the output of a print_r() after each iteration of the while loop so you can see it running through the divisions, multiplications, additions and subtractions one by one and thn modifying the array as it goes:
Array ( [0] => 35 [1] => - [2] => 59 [3] => * [4] => 2 [5] => / [6] => 27 [7] => * [8] => 2 )
Array ( [0] => 35 [1] => - [2] => 59 [3] => * [4] => 0.0740740740741 [5] => * [6] => 2 )
Array ( [0] => 35 [1] => - [2] => 4.37037037037 [3] => * [4] => 2 )
Array ( [0] => 35 [1] => - [2] => 8.74074074074 )
Array ( [0] => 26.2592592593 )

Answer 3

Why not calculate as you go splitting the input into an array, and then just output the result?
Just as an example:
$input = "35-59*2/27*2";
if (preg_match('/[^-+*\/\\d]/', $input)) // simple checking
{
echo "just use numbers and 4 operators!";
}
else
{
$substraction = explode('-', $input);
foreach ($substraction as $pos_s => $sub)
{
$addition = explode('+', $sub);
foreach ($addition as $pos_a => $add)
{
$multiplication = explode('*', $add);
foreach ($multiplication as $pos_m => $mult)
{
$division = explode('/', $mult);
$d = $division[0];
for ($i=1; $i < count($division);$i++)
$d = $d / $division[$i];
$multiplication[$pos_m] = $d;
}
$m = $multiplication[0];
for ($i=1; $i < count($multiplication);$i++)
$m = $m * $multiplication[$i];
$addition[$pos_a] = $m;
}
$a = $addition[0];
for ($i=1; $i < count($addition);$i++)
$a = $a + $addition[$i];
$substraction[$pos_s] = $a;
}
$result = $substraction[0];
for ($i=1; $i < count($substraction);$i++)
$result = $result - $substraction[$i];
echo $input . " = " . $result;
}
prints
35-59*2/27*2 = 26.259259259259