How to count how many times a value appears in a table?
Example:
<table id="table">
<tr>
<td> 2 </td>
</tr>
<tr>
<td> 6 </td>
</tr>
<tr>
<td> 2 </td>
</tr>
<tr>
<td> 1 </td>
</tr>
</table>
O 2 appears twice, 6 once and 1 once ...
OBS: remembering that numbers change and are random ...
You can create HTML elements to save / view the count:
$('#table td').each(function (i, e) {
if ($('[data-numero=' + $(this).text() + ']').length) {
var numero = $('[data-numero=' + $(this).text() + ']').children('span');
numero.text( parseInt(numero.text()) + 1 );
} else {
$('body').append('<div data-numero="' + $(this).text() + '">Número ' + $(this).text() + ': <span>1</span></div>');
}
});
See working on JSFiddle
Just use a dictionary that has the values in the cells as keys;)
Type like this:
var dicionarioDeValores = {};
$("#table")
.find("td")
.each(function (index, elem) {
var valor = $(elem).text();
if (!dicionarioDeValores[valor]) {
dicionarioDeValores[valor] = 1;
} else {
dicionarioDeValores[valor]++;
}
});
You will go through all the cells. Each time you enter a cell, if its value is already key to the dictionary, you increment. Otherwise, you start with 1. Good luck and happy coding!
I decided to do it in pure Javascript, just to have one more search option:
<!DOCTYPE HTML>
<html>
<head>
<meta charset="utf-8">
<title>Tabela</title>
<script type="text/javascript">
Calcular = function(id){
var table = document.getElementById(id);
var td = table.getElementsByTagName('td');
var dados = {};
for(i = 0; i < td.length; i++)
{
dados[td[i].innerHTML] = (dados[td[i].innerHTML] === undefined)? 1: (dados[td[i].innerHTML] + 1);
}
console.log(dados);
}
</script>
</head>
<body>
<table id="table">
<tr>
<td>2</td>
</tr>
<tr>
<td>6</td>
</tr>
<tr>
<td>2</td>
</tr>
<tr>
<td>1</td>
</tr>
<tr>
<td>1</td>
</tr>
<tr>
<td>1</td>
</tr>
</table>
<button type="button" onclick="Calcular('table')">Calcular</button>
</body>
</html>
Example Online: JsFiddle >
Note: in my example there is more td and so the numbering changes.
This is a case where you can benefit from associative arrays .
//Array associativo
var histograma = {};
// A função abaixo é chamada para cada célula:
$('table#table tr td').each(function() {
var chave = $(this).text(); // A chave do histograma
var val = histograma[chave] || 0; //Caso o valor não exista, assuma zero
histograma[chave] = val + 1; //Contagem de ocorrências
});
// Listando o resultado do método acima:
for (var chave in histograma) {
$('#res').append(chave + ':' + histograma[chave] + '<br/>');
}
The result of this snippet is as follows:
Tabela:
2
6
2
1
Ocorrências:
2 :2
6 :1
1 :1
(Edit - after reading the other answers, this is basically a slightly leaner version of the response from Renan