I have an object:
[{"Spalte":3}]
How can I get only 3 ?
I tried something like that:
var s = JSON.stringify(data); // [{"Spalte":3}] as String
var d = parseInt(s); // typeof d = number,
When I tried to alert(d) I receive NaN.
3 Answers
You probably meant to do
var d = JSON.parse(s)[0].Spalte;
s contains a serialization of an object as JSON. So we parse it with JSON.parse to get back the original object and then use standard javascript to extract the numeric field. Notice there is no need for parseInt.
Alternatively, you can stringify the numeric field by itself:
var data = [{"Spalte":3}];
var s = JSON.stringify(data[0].Spalte);
var d = JSON.parse(s);
or even:
var data = [{"Spalte":3}];
var s = data[0].Spalte + ""; // simply convert a number to string
var d = parseInt(s); // parse the string back to a number.
2 Comments
Goujon
There is absolutely no need to use any JSON.* methods or string parsing. As Maxx already commented, a very simple
data[0].Spalte does the trick. Also, you probably meant JSON.parse(s) instead of JSON.parse('3')?
Dan Froberg
Question is about stingify data and parsing a number out of it, not about what others believe about others having mistakes in the question. The mistake is the beliefe that the parseInt parse the int out from a string. To believe JSON.stringify is JSON.parse is unbelieveblabb.
var data = [{
"Spalte": 3,
valueOf() {
return Spalte;
}
}];
console.log(+data[0]) // 3
Comments
The obvious answer is:
var data = [{"Spalte":3}]
console.log(data[0].Spalte); //output number
If it is a string as others has proposed:
var data = '[{"Spalte":3}]'
//replace non-digits with nothing
data = data.replace(/[^0-9]*/g, '');
console.log(data); //output string
data[0].Spalte?