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Editor to share with you what is the use of Promise in js. I hope you will get something after reading this article. Let's discuss it together.

1. Promise can be in the wait state (pending) waiting to be assigned, and the value can be given and converted to the solution state (resolved).

2. Once promise is lost by a value resolve, it will always keep that value from being lost by resolve.

Example

Function Promise (fn) {var state = 'pending'; var value; var deferred; function resolve (newValue) {value = newValue; state =' resolved'; if (deferred) {handle (deferred);}} function handle (onResolved) {if (state = 'pending') {deferred = onResolved; return;} onResolved (value);} this.then = function (onResolved) {handle (onResolved);} Fn (resolve);} after reading this article, I believe you have a certain understanding of "what is the use of Promise in js". If you want to know more about it, welcome to follow the industry information channel. Thank you for reading!

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