Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
570 views
in Technique[技术] by (71.8m points)

dictionary - First item from a Map on JavaScript ES2015

I have a Map like this:

const m = new Map();
m.set('key1', {})
.
m.set('keyN' {})

the Mapcan have 1 or many items. Can I get the first item by index, without m.get('key1') and without a iterator loop?

like: m.get()[0]

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Answer

0 votes
by (71.8m points)

Use the Map.prototype.entries function, like this

const m = new Map();
m.set('key1', {})
m.set('keyN', {})

console.log(m.entries().next().value); // [ 'key1', {} ]

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...