I got a function which should save multiple JSON Objects into an Array of the Type "Contact"

getContacts(){
    let self = this;
    $.ajax({
        type: "GET",
        url: "/chat/contacts/",
        dataType:"json",
        success: function(response){
            let obj = response;
            let i = 1;
            let contacts: Contact[] = [];
            for (let key in obj) {
                if (obj.hasOwnProperty(key)) {
                    let val = obj[key];
                    contacts[i].id = val["id"]; //<-- contacts[i] is undefinded
                    contacts[i].partner = val["partnerId"];
                    contacts[i].name = val["name"];
                    contacts[i].type = val["type"];
                    console.log(contacts[i]);
                }
            }
        },
        error: function(jqXHR, textStatus, errorThrown){
            alert(errorThrown);
        }
    });
}

At the marked point it says

contacts[i] is undefinded

How do i have to initialize the Array to make it working?

Here is the Contact Class:

class Contact extends BaseModel{
    static CCO_ID = "id";
    static CCO_PARTNER = "partner";
    static CCO_NAME = "name";
    static CCO_TYPE = "type";


    partner: Number;
    name: String;
    type: Number;
}

I got a function which should save multiple JSON Objects into an Array of the Type "Contact"

getContacts(){
    let self = this;
    $.ajax({
        type: "GET",
        url: "/chat/contacts/",
        dataType:"json",
        success: function(response){
            let obj = response;
            let i = 1;
            let contacts: Contact[] = [];
            for (let key in obj) {
                if (obj.hasOwnProperty(key)) {
                    let val = obj[key];
                    contacts[i].id = val["id"]; //<-- contacts[i] is undefinded
                    contacts[i].partner = val["partnerId"];
                    contacts[i].name = val["name"];
                    contacts[i].type = val["type"];
                    console.log(contacts[i]);
                }
            }
        },
        error: function(jqXHR, textStatus, errorThrown){
            alert(errorThrown);
        }
    });
}

At the marked point it says

contacts[i] is undefinded

How do i have to initialize the Array to make it working?

Here is the Contact Class:

class Contact extends BaseModel{
    static CCO_ID = "id";
    static CCO_PARTNER = "partner";
    static CCO_NAME = "name";
    static CCO_TYPE = "type";


    partner: Number;
    name: String;
    type: Number;
}

• javascript
• arrays
• json
• typescript

• use contacts.push – N1gthm4r3 Commented Aug 31, 2017 at 6:57

1 Answer 1

You need first to define that contacts[i] is an object and then use it's properties.

And one more thing, you are starting from index 1, in Javascript array's index is starting from 0. Be aware if that is not intentionally.

let val = obj[key];
contacts[i] = new Contact(); // <-- Look here
contacts[i].id = val["id"];
contacts[i].partner = val["partnerId"];
contacts[i].name = val["name"];
contacts[i].type = val["type"];
console.log(contacts[i]);