it seems to be a really easy question, but I am a little bit struggling: I am receiving a JSON String via JavaScript. Now I would like to iterate through the element. The resulting string has this form: {"title":value,"title2":value}
How can I iterate through this JSON string without knowing the key and value? I would like to get this output:
title -> value
title2 -> value2
I tried it this way:
$json = file_get_contents('php://input');
$array = json_decode($json,true);
$response = "Test";
foreach($array as $key=>$val) {
$response = $response. "$key : $val";
}
echo json_encode($response);
It only returns "Test". If I change it to echo json_encode($array), it returns the mentioned JSON String.
You mention javascript and php in your question, so I'm going to answer for both. Here is JS, two different ways. I believe that foreach is being deemphasized in favor of the (of) construct now, but I don't work primarily in JS:
var json = '{"title": 12, "title2": "text"}';
var data = JSON.parse(json);
Object.keys(data).forEach(function(key) {
console.log(key + ' -> ' + data[key])
})
for(key of Object.keys(data)) {
console.log(key + ' -> ' + data[key]);
}
And for PHP:
You can parse the json string into an array using json_decode:
$json = '{"title": 12, "title2": "text"}';
$arr = json_decode($json, true);
foreach($arr as $key=>$val) {
echo "$key : $val";
}
true parses it into an array instead of a std object.
https://www.php.net/manual/en/function.json-decode.php
Because of response's format you must decode the decoded format in order to take the object as you want
$json = '{"title": 12, "title2": "text"}';
$encoded=json_encode($json);
$decoded=json_decode($encoded);
$ddecode=json_decode($decoded);
foreach($ddecode as $key=>$val) {
echo "$key -> $val";
}
Output :
title -> 12 title2 -> text
I have a string like
Deser't - & Fest !
how to format this string is seo friendly like Desert-Fest.
In php I use the above function
function cleanString($str, $separator = "-"){
$q_separator = preg_quote($separator);
$trans = array(
'&.+?;' => '',
'[^a-z0-9 _-]' => '',
'\s+' => $separator,
'('.$q_separator.')+' => $separator
);
$str = strip_tags($str);
foreach ($trans as $key => $val){
$str = preg_replace("#".$key."#i", $val, $str);
}
$str = strtolower($str);
return trim($str, $separator);
}
How to do this in Jquery?
Thanks.
Half of your solution is to HTML-decode the entities in the input. That can be done in JS like this, or jQuery like this.
From there you can use a regular expression to remove any characters from the resulting string that you don't want, like this:
function htmlDecode(input) {
var e = document.createElement('textarea');
e.innerHTML = input;
return e.childNodes.length === 0 ? "" : e.childNodes[0].nodeValue;
}
let input = "Deser't - & Fest !";
let output = htmlDecode(input);
output = output.replace(/[^a-z-]/gi, ''); // remove anything that isn't a-Z or -
console.log(output);
I want to calculate math expression from a string. I have read that the solution to this is to use eval(). But when I try to run the following code:
<?php
$ma ="2+10";
$p = eval($ma);
print $p;
?>
It gives me the following error:
Parse error: syntax error, unexpected $end in
C:\xampp\htdocs\eclipseWorkspaceWebDev\MandatoryHandinSite\tester.php(4)
: eval()'d code on line 1
Does someone know the solution to this problem.
While I don't suggest using eval for this (it is not the solution), the problem is that eval expects complete lines of code, not just fragments.
$ma ="2+10";
$p = eval('return '.$ma.';');
print $p;
Should do what you want.
A better solution would be to write a tokenizer/parser for your math expression. Here's a very simple regex-based one to give you an example:
$ma = "2+10";
if(preg_match('/(\d+)(?:\s*)([\+\-\*\/])(?:\s*)(\d+)/', $ma, $matches) !== FALSE){
$operator = $matches[2];
switch($operator){
case '+':
$p = $matches[1] + $matches[3];
break;
case '-':
$p = $matches[1] - $matches[3];
break;
case '*':
$p = $matches[1] * $matches[3];
break;
case '/':
$p = $matches[1] / $matches[3];
break;
}
echo $p;
}
Take a look at this..
I use this in an accounting system where you can write math expressions in amount input fields..
Examples
$Cal = new Field_calculate();
$result = $Cal->calculate('5+7'); // 12
$result = $Cal->calculate('(5+9)*5'); // 70
$result = $Cal->calculate('(10.2+0.5*(2-0.4))*2+(2.1*4)'); // 30.4
Code
class Field_calculate {
const PATTERN = '/(?:\-?\d+(?:\.?\d+)?[\+\-\*\/])+\-?\d+(?:\.?\d+)?/';
const PARENTHESIS_DEPTH = 10;
public function calculate($input){
if(strpos($input, '+') != null || strpos($input, '-') != null || strpos($input, '/') != null || strpos($input, '*') != null){
// Remove white spaces and invalid math chars
$input = str_replace(',', '.', $input);
$input = preg_replace('[^0-9\.\+\-\*\/\(\)]', '', $input);
// Calculate each of the parenthesis from the top
$i = 0;
while(strpos($input, '(') || strpos($input, ')')){
$input = preg_replace_callback('/\(([^\(\)]+)\)/', 'self::callback', $input);
$i++;
if($i > self::PARENTHESIS_DEPTH){
break;
}
}
// Calculate the result
if(preg_match(self::PATTERN, $input, $match)){
return $this->compute($match[0]);
}
// To handle the special case of expressions surrounded by global parenthesis like "(1+1)"
if(is_numeric($input)){
return $input;
}
return 0;
}
return $input;
}
private function compute($input){
$compute = create_function('', 'return '.$input.';');
return 0 + $compute();
}
private function callback($input){
if(is_numeric($input[1])){
return $input[1];
}
elseif(preg_match(self::PATTERN, $input[1], $match)){
return $this->compute($match[0]);
}
return 0;
}
}
I recently created a PHP package that provides a math_eval helper function. It does exactly what you need, without the need to use the potentially unsafe eval function.
You just pass in the string version of the mathematical expression and it returns the result.
$two = math_eval('1 + 1');
$three = math_eval('5 - 2');
$ten = math_eval('2 * 5');
$four = math_eval('8 / 2');
You can also pass in variables, which will be substituted if needed.
$ten = math_eval('a + b', ['a' => 7, 'b' => 3]);
$fifteen = math_eval('x * y', ['x' => 3, 'y' => 5]);
Link: https://github.com/langleyfoxall/math_eval
Using eval function is very dangerous when you can't control the string argument.
Try Matex for safe Mathematical formulas calculation.
Solved!
<?php
function evalmath($equation)
{
$result = 0;
// sanitize imput
$equation = preg_replace("/[^a-z0-9+\-.*\/()%]/","",$equation);
// convert alphabet to $variabel
$equation = preg_replace("/([a-z])+/i", "\$$0", $equation);
// convert percentages to decimal
$equation = preg_replace("/([+-])([0-9]{1})(%)/","*(1\$1.0\$2)",$equation);
$equation = preg_replace("/([+-])([0-9]+)(%)/","*(1\$1.\$2)",$equation);
$equation = preg_replace("/([0-9]{1})(%)/",".0\$1",$equation);
$equation = preg_replace("/([0-9]+)(%)/",".\$1",$equation);
if ( $equation != "" ){
$result = #eval("return " . $equation . ";" );
}
if ($result == null) {
throw new Exception("Unable to calculate equation");
}
echo $result;
// return $equation;
}
$a = 2;
$b = 3;
$c = 5;
$f1 = "a*b+c";
$f1 = str_replace("a", $a, $f1);
$f1 = str_replace("b", $b, $f1);
$f1 = str_replace("c", $c, $f1);
evalmath($f1);
/*if ( $equation != "" ){
$result = #eval("return " . $equation . ";" );
}
if ($result == null) {
throw new Exception("Unable to calculate equation");
}
echo $result;*/
?>
This method has two major drawbacks:
Security, php script is being evaluated by the eval function. This is bad,
especially when the user wants to inject malicious code.
Complexity
I created this, check it out: Formula Interpreter
How does it work ?
First, create an instance of FormulaInterpreter with the formula and its parameters
$formulaInterpreter = new FormulaInterpreter("x + y", ["x" => 10, "y" => 20]);
Use the execute() method to interpret the formula. It will return the result:
echo $formulaInterpreter->execute();
in a single line
echo (new FormulaInterpreter("x + y", ["x" => 10, "y" => 20]))->execute();
Examples
# Formula: speed = distance / time
$speed = (new FormulaInterpreter("distance/time", ["distance" => 338, "time" => 5]))->execute() ;
echo $speed;
#Venezuela night overtime (ordinary_work_day in hours): (normal_salary * days_in_a_work_month)/ordinary_work_day
$parameters = ["normal_salary" => 21000, "days_in_a_work_month" => 30, "ordinary_work_day" => 8];
$venezuelaLOTTTArt118NightOvertime = (new FormulaInterpreter("(normal_salary/days_in_a_work_month)/ordinary_work_day", $parameters))->execute();
echo $venezuelaLOTTTArt118NightOvertime;
#cicle area
$cicleArea = (new FormulaInterpreter("3.1416*(radio*radio)", ["radio" => 10]))->execute();
echo $cicleArea;
About the formulas
It must contain at least two operands and an operator.
Operands' name could be in upper or lower case.
By now, math functions as sin, cos, pow… are not included. I'm working to include them.
If your formula is not valid, you will get an error message like: Error, your formula (single_variable) is not valid.
Parameters' values must be numeric.
You can improve it if you want to!
eval Evaluates the given code as PHP. Meaning that it will execute the given paremeter as a PHP piece of code.
To correct your code, use this :
$ma ="print (2+10);";
eval($ma);
Using eval function
protected function getStringArthmeticOperation($value, $deduct)
{
if($value > 0){
$operator = '-';
}else{
$operator = '+';
}
$mathStr = '$value $operator $deduct';
eval("\$mathStr = \"$mathStr\";");
$userAvailableUl = eval('return '.$mathStr.';');
return $userAvailableUl;
}
$this->getStringArthmeticOperation(3, 1); //2
Finding a sweetspot between the dangers of eval and the limitless calculation possibilities I suggest checking the input for only numbers, operators and brackets:
if (preg_match('/^[0-9\+\-\*\/\(\)\.]+$/', $mathString)) {
$value = eval('return
' . $mathString . ';');
} else {
throw new \Exception('Invalid calc() value: ' . $mathString);
}
It's still easy to use yet relatively save. And it can handle any basic math calulation like (10*(1+0,2)) which isn't possible with most of the mentioned solutions here.
An eval'd expression should end with ";"
Try this :
$ma ="2+10;";
$p = eval($ma);
print $p;
By the way, this is out of scope but the 'eval' function won't return the value of the expression. eval('2+10') won't return 12.
If you want it to return 12, you should eval('return 2+10;');
I am receiving a serialized string into a PHP function (sent via Ajax to PHP). Let's say it looks like this:
year=1923&season=Winter&person_1_name=barry&person_1_age=20&person_2_name=Tom&person_3_name=Jane&person_3_age=30
I need to know how in PHP to split those numbered fields out so I can do something with them, like:
foreach ( person_x as person ) {
// do something here with person_x's details
}
Also I can't generalise the information I will receive as some may not have all the info (note person_2 does not have an age in the above example) and there will be an unknown number of these fields (they are repeatable in the form)
Using parse_str() Recommended method
$string = 'year=1923&season=Winter&person_1_name=barry&person_1_age=20&person_2_name=Tom&person_3_name=Jane&person_3_age=30';
parse_str($string, $output);
foreach ($output as $key => $person){
echo $key . " = " . $person . "<br />";
}
Using explode()
$string = 'year=1923&season=Winter&person_1_name=barry&person_1_age=20&person_2_name=Tom&person_3_name=Jane&person_3_age=30';
$persons = explode("&", $string);
foreach ($persons as $person){
$details = explode("=", $person);
echo $details[0] . " = " . $details[1] . "<br />";
}
Output:
year = 1923
season = Winter
person_1_name = barry
person_1_age = 20
person_2_name = Tom
person_3_name = Jane
person_3_age = 30
----------
year = 1923
season = Winter
person_1_name = barry
person_1_age = 20
person_2_name = Tom
person_3_name = Jane
person_3_age = 30
Exclude all other fields that don't start with person_
parse_str($string, $output);
foreach ($output as $key => $person){
if(preg_match('/person_/', $key)){
echo $key . " = " . $person . "<br />";
}
}
Output:
person_1_name = barry
person_1_age = 20
person_2_name = Tom
person_3_name = Jane
person_3_age = 30
I am echoing a while loop results from php into Javascript, Javascript is picking it up in AJAX success function and displaying it in html.
The problem i am facing is, the number of times the for loop is repeating itself is the number of letters, characters, i am not sure why, i attached an image to display what i mean Thanks for your time!
I tried echoing it directly in php and echoing it in JSON format, both ways is creating the same problem.
$result=mysqli_query($con,"SELECT * FROM list WHERE Listingid = '$Listingid' AND Status ='Bird'");
while($row = mysqli_fetch_array($result))
{
$output[] = $row;
}
if (!empty($output)){
echo json_encode( $output );}
else{
echo json_encode( [] );
}
Javascript
<script>
function gup( name )
{
name = name.replace(/[\[]/,"\\\[").replace(/[\]]/,"\\\]");
var regexS = "[\\?&]"+name+"=([^&#]*)";
var regex = new RegExp( regexS );
var results = regex.exec( window.location.href );
if( results == null )
return null;
else
return results[1];
}
var frank_param1 = gup( 'Listingid' );
$("#display12").append(frank_param1);
console.log(frank_param1)
$.ajax({
type: "POST",
url: "interestedwaiting.php",
data: {"data":frank_param1},
success: function(data2){
for(var i=0; i<data2.length; i++) {
console.log(data2)
var html1 = "<div class=two> Listingid : " + data2[i] + "</div>";
$('#display12').append(html1);
}}
});
</script>