lab2a-promise.js

///// Problem 1 - Fun with Promises

function flip() {
    let p = new Promise(function (resolve, reject) {
        if (Math.random() > 0.5) resolve();
        else reject();
    });
    return p;
}

//// Add code here that will "flip" the coin ten times and write the 
//// result to the console (e.g. "Heads" or "Tails" for each flip).
for (let i = 0; i < 10; i++) {
    flip().then(() => console.log("Heads!"), () => console.log("Tails!"));
}



///// Problem 2 - More fun...

function countBig(bignum) {
    // Add code here that returns a Promise that will resolve after it has counted to bignum

    return new Promise((resolve, reject) => {
        for (let i = 0; i < bignum; i++) {
            // just counting here...
        }
        resolve();
    })
}


start = Date.now();
bignum = 1000000000;
countBig(1000000000).then(()=> {
    console.log("It took " + (Date.now() - start) + " ms to count to " + bignum);
}, () => {
    console.log("A problem occurred while trying to count to " + bignum);
})