I have a form with several multiple-choice questions on a page and using serializeArray gives me an array like
[
{
name: "question1",
value: "a"
},
{
name: "question2",
value: "a"
},
{
name: "question3",
value: "b"
}
]
and so on (each question have answer options a, b and c).
How can I count the frequency of each answer (a, b and c) in the array and have the counts as variables (a = 2, b = 1 in the case above)?
You don't need jQuery at all for that.
var array = [
{
name: "question1",
value: "a"
},
{
name: "question2",
value: "a"
},
{
name: "question3",
value: "b"
}
]
var counts = {};
array.forEach(function(element) {
if (!counts[element.value]) {
counts[element.value] = 0;
}
counts[element.value] += 1;
});
console.log(counts);
// Output :
// {"a" : 2, "b" : 1}
Something like that :
var countArray = {}
$.each(dataArray, function(index, value){
if(countArray[value.value] == undefined)
countArray[value.value] = 0;
countArray[value.value]++;
});
Try this : You can iterate the answer array and keep the count in seperate map where answer value is the key. See below code -
var answerArray = [
{
name: "question1",
value: "a"
},
{
name: "question2",
value: "a"
},
{
name: "question3",
value: "b"
}
];
var countMap = {};
$.each(answerArray, function(k, v){
countMap[v.value] = (countMap[v.value])? (parseInt(countMap[v.value])) + 1 : 1;
});
alert(JSON.stringify(countMap));<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>simple:
var answers = [
{
name: "question1",
value: "a"
},
{
name: "question2",
value: "a"
},
{
name: "question3",
value: "b"
}
]
var histogram = {};
for ( var n = 0; n <answers.length; n++ )
{
if ( !histogram[answers[n].value] )
histogram[answers[n].value] = 1;
else
histogram[answers[n].value] ++;
}
should give :
{
"a": 2,
"b": 1,
}
Compact jQuery solution:
var count = {a: 0, b: 0, c: 0};
$(array).map(function(){
count[this.value]++;
});
Which gives you in the end:
{a: 2, b: 1, c: 0}
