How to get values from a promise with node.js without .then function

Question

I have a problem with a promise using node.js. My code is below:

var p1 = new Promise(function(resolve, reject) {
  // my function here
});

p1.then(function(result){
  // my result
});

This code works but to get values from p1 I must use the .then method and my result values can be accessed just on p1.then. How do I access p1 values without .then?

Below are my expected results:

var p1 = new Promise(function(resolve, reject) {
      // my function here
    });

var abc = NextFunction(p1);

The p1 values will be used afterwards in code outside of the p1 variable.

Answer 1

p1 is a Promise, you have to wait for it to evaluate and use the values as are required by Promise.

You can read here: http://www.html5rocks.com/en/tutorials/es6/promises/

Although the result is available only inside the resolved function, you can extend it using a simple variable

var res;
p1.then(function(result){
    res = result; // Now you can use res everywhere
});

But be mindful to use res only after the promise resolved, if you depend on that value, call the next function from inside the .then like this:

var res;
p1.then(function(result){
    var abc = NextFunction(result);
});

Answer 2

You can use await after the promise is resolved or rejected.

function resolveAfter2Seconds(x) { 
    return new Promise(resolve => {
        setTimeout(() => {
            resolve(x);
        }, 2000);
    });
}

async function f1() {
    var x = await resolveAfter2Seconds(10);
    console.log(x); // 10
}

f1();

Be aware await expression must be inside async function though.