我正在尝试从数组内的对象中推送值

Question

I am trying to push data coming from an array of objects (key/value), then pushing it inside an array, to display them later.

I have already tried doing the push inside the array but till now it is always giving undefined for the total amount of items being pushed.

//array
var clients_array = '[{"code": "1", "name": "client 1"}, 
{"code": "2", "name": "client 2"}, {"code": "3", "name": "client 3"}]';

var displayClient = [];

var json_parse1 = JSON.parse(clients_array);
json_parse1.forEach(function(client){
    console.log(client.code + ' - ' + client.name);
    displayClient.push(client.code + ' - ' + client.name);
    alert(displayClient[i]);
})

Using the above code, In the console.log I am getting the correct data which I would like to push. But when alerting the displayClient array, which in this case should be filled with the console.logged data, it displays undefined for each data. Hence, I would like to push the correct data as displayed in the console.log.

Answer 1

You need to add a parameter for i in the callback function.

json_parse1.forEach(function (client, i) {
                                      ^

 var clients_array = '[{"code": "1", "name": "client 1"}, {"code": "2", "name": "client 2"}, {"code": "3", "name": "client 3"}]'; var displayClient = []; var json_parse1 = JSON.parse(clients_array); json_parse1.forEach(function (client, i) { console.log(client.code + ' - ' + client.name); displayClient.push(client.code + ' - ' + client.name); alert(displayClient[i]); }) console.log(displayClient); 

A better approach would be to use Array#map and return the new items.

 var array = [{ code: "1", name: "client 1" }, { code: "2", name: "client 2" }, { code: "3", name: "client 3" }], displayClient = array.map(({ code, name }) => [code, name].join(' - ')); console.log(displayClient);