Difference between initializing using ternary condition vs bracket initialization-CodePudding

I just come across of this variable initialization

let { page = 1 } = req.query;

where if req.query.page doesn't exist, page = 1. But if there is req.query.page (let say 6), page = 6

I just want to ask if there is any difference the above initialization on this

let page = req.query.page? req.query.page : 1

and at this point I like using the first since it's less in code. Any idea how the first one works?

CodePudding user response：

The difference is that the default destructuring syntax will assign 1 only if the property is undefined. In contrast, the conditional operator will assign whenever the property is falsy.

const req = { query: {
  page: 0
}};

let { page = 1 } = req.query;
console.log(page);

const req = { query: {
  page: 0
}};

let page = req.query.page? req.query.page : 1
console.log(page);

So it's slightly different, but doing let { page = 1 } = req.query; should be fine as long as you keep in mind what it means.