I have an array of json objects from the server:
var a = [
{id:1,name:"Piano",class:"Instrument"},
{id:2,name:"Guitar",class:"null"},
{id:3,name:"null",class:"null"},.....]
Using underscorejs, is it possible to loop through these objects and change every "null" value in every key with empty string ""?
Iterate through the collection and its objects using _.each()* method and replace the values equal to "null" with the empty string.
So the logic is the same as you were iterating through two-dimensional array using nested loop.
* I don't suggest to use _.map() here since this method will produce new modified array and I don't know if you need this, though if you want you can also map the array using _.each(obj) inside the mapping function.
var arr,
searchVal,
replaceVal;
arr = [
{id: 1, name: "Piano", class: "Instrument"},
{id: 2, name: "Guitar", class: "null"},
{id: 3, name: "null", class: "null"}
];
searchVal = "null";
replaceVal = "";
_.each(arr, function(obj) {
_.each(obj, function(value, key) {
if(value === searchVal) {
obj[key] = replaceVal;
}
});
});
console.log(arr);<script src="https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.7.0/underscore-min.js"></script>Instead of looping through all the data after being parsed from your JSON string, you could just create a custom parser for JSON.parse and save yourself some time.
function customParser(key, value) {
if (value.name === 'null') {
value.name = '';
}
if (value.class === 'null') {
value.class = '';
}
return value;
}
var jsonText = '[{"id":1,"name":"Piano","class":"Instrument"},{"id":2,"name":"Guitar","class":"null"},{"id":3,"name":"null","class":"null"}]',
a = JSON.parse(jsonText, customParser);
document.body.appendChild(document.createTextNode(JSON.stringify(a)));
