如何根据条件（例如 Node.js 中的值数组是否为空）有选择地向对象数组中的对象插入键

Question

Here is the sample code block where I am inserting an object to an array of object through push method :

let sent_by;
let timestamp;
let txt;
let all_links = [];
let all_images = [];

data_object['messages'].push({
'sent_by' : sent_by,
'timestamp' : timestamp,
'content' : txt,
'links' : all_links,
'images' : all_images
})

How can I stop inserting the keys - content (string) , links (array) or images (array) to the array of objects when they are empty effectively in Node.js.

Answer 1

You can use the spread operator to conditionally add an element:

data_object["messages"].push({
  sent_by: sent_by,
  timestamp: timestamp,
  ...(txt && { content: txt }),
  ...(all_links.length > 0 && { links: all_links }),
  ...(all_images.length > 0 && { images: all_images })
});

Answer 2

Use a simple if statement in your control structure:

if (txt && links.length && all_images.length) {
  data_object['messages'].push({
  'sent_by' : sent_by,
  'timestamp' : timestamp,
  'content' : txt,
  'links' : all_links,
  'images' : all_images
  })
}

Only those elements who have the 3 props, will be pushed to the array