Passing Arguements to Promises

Question

I need to pass some arguments to a promise but promises only take two parameters (resolve and reject). I've seen similar questions about passing arguments into .then() functions, but none about the promises themselves. Is there a way to make it work? If not, any suggestions for work around would be greatly appreciated. Thanks

Answer 1

Broadly it can be along these lines (using closure). Let me know if it solves your use case. Else, let me know.

function asyncFunction(arg1, arg2 ... ) {
    return new Promise(function(resolve, reject){
        //use arg1, arg2 and so on. And, after your async call 
        if(arg1 === true) {
           setTimeout(resolve,200) //e.g. async function
       } else {
            reject(arg2)
       }
    })
}

And, finally don't forget to call:

asyncFunction(true, 2)

Answer 2

Anything you use to resolve the promise with, will be used as the parameters for the .then() call following that promise:

 // A function containing a promise. const get_data = () => { return new Promise(( resolve, reject ) => { // some logic determining if the promise has to resolve or reject. const valid = true; // Pass all different parameters as a object we can destructure. if ( valid ) resolve({ num: 1, str: 'some string', ary: [ 'data' ] }); else reject( new Error( 'something went wrong' )); }); }; // Call the function that returns the promise. get_data() // destructure the object back into individual variables. .then(({ num, str, ary }) => { // Do things with the parameters. console.log( `the number parameter is: ${ num }` ); console.log( `the string parameter is: ${ str }` ); console.log( `the array parameter is: ${ ary }` ); }) // Catch any erros in the promise chain. .catch( error => { console.error( 'The promise rejected' ); throw error; });