Find object in array using Javascript/Jquery

Question

I need to loop through the data array using the following function and return 'True' in case the function finds an object with particular values. However, when I fire the function it returns the following error message:

Cannot read property 'isTrue' of undefined

Could you please take a look and explain what I am doing wrong?

var data = [
 {
 category: "1",
 values: [
 { key: "valueToGet1", isTrue:"true" },
 { key: "valueToGet2", isTrue:"false" }
 ]
 },
 {
 category: "2",
 values: [
 { key: "valueToGet3", isTrue:"false"},
 { key: "valueToGet4", isTrue:"true"}
 ]
 }
 ]
var getValue = function (value) {
 var result;
 $.each(data, function (i, item) {
 result = $.grep(item.values, function (e) {
 return e.key == value;
 })[0];
 })
 return result.isTrue == 'true';
}
 
console.log(getValue('valueToGet4')); //should return true;

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

• Amruth: refer the link stackoverflow.com/questions/41197554/…
• Marcos Pérez Gude: The error said that result is undefined, so some problem you have with data object I guess. Did you try to pass the whole array as parameter? getValue('valueToGet4', data) and the definition: var getValue = function(value, array)

Answer 1

You can use .some()

var getValue = function(value) {
 //Iterate each element in the array
 return data.some(d => {
 //iterate values property of the array item
 return d.values.some(v => {
 return v.key == value && v.isTrue == "true";
 })
 });
}

var data = [{
 category: "1",
 values: [{
 key: "valueToGet1",
 isTrue: "true"
 }, {
 key: "valueToGet2",
 isTrue: "false"
 }]
}, {
 category: "2",
 values: [{
 key: "valueToGet3",
 isTrue: "false"
 }, {
 key: "valueToGet4",
 isTrue: "true"
 }]
}]
var getValue = function(value) {
 return data.some(d => {
 return d.values.some(v => {
 return v.key == value && v.isTrue == "true"
 })
 });
}
console.log(getValue('valueToGet4')); //should return true;

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

• egurb: Thanks, most appropriate one!

Answer 2

Use Reduce to exclude the items you don't want:

var getValue = function (value) {
 var result = data.filter(function (item) {
 result = item.values.filter(function (e) {
 return e.key == value && e.isTrue == 'true';
 });
 return result.length > 0 
 })
 return result.length > 0 ;
} 

• egurb: thanks for another solution, will definitely consider using this