JSON array filter does not apply

Question

I am trying to filter the data from an array, but it is throwing an error saying

filter() is not function

Here is the code:

var selectedObject = [];
selectedObject= JSON.stringify(formsDataSource.data());
//console.log(selectedObject);

//var filtered = $.grep(selectedObject, function (el) {
//    return el.po_order_no = 18;
//});
//console.log((filtered));
if (selectedObject == undefined) {
    alert("Undefined");
} else {
    var data= selectedObject.filter(function (element) { return element.po_order_no = "18"; })
    alert("" + data);
}

I tried many things but it is still throwing an error. Any help?

Answer 1

In return statement you have to compare value not assigning the value.

Change:

return element.po_order_no = "18";

To

return element.po_order_no == "18";

Also there might be some issues with the data. Solution with sample data:

 var selectedObject = [ { age: 25, po_order_no: "25" }, { age: 22, po_order_no: "18" }, { age: 15, po_order_no: "20" } ]; if (selectedObject == undefined) { console.log("Undefined"); } else { var data= selectedObject.filter(function (element) { return element.po_order_no == "18"; }) console.log(data); } 

Answer 2

Few observations :

• selectedObject= JSON.stringify(formsDataSource.data());

  This statement states that selectedObject is a string. A string does not have a filter() method.

• condition inside filter function should be element.po_order_no == "18" instead of element.po_order_no = "18"

Solution :

 var selectedObject = [ { "po_order_no": 18, "po_order_name": "abc" }, { "po_order_no": 19, "po_order_name": "xyz" } ]; if (selectedObject == undefined) { console.log("Undefined"); } else { var data = selectedObject.filter(element => element.po_order_no == "18") console.log(data); }