How do I use loop in Firebase function?

Question

I want to run loop in Firebase function sample data set:

I want to loop through it and print console.log hello

Output should be like:

Answer 1

Try this;

sampleDataSet.forEach((d)=>{
  console.log("Hello "  + d.firstName + " " + d.lastName);
})

if sampleDataSet is an object then we can loop object as well;

for (let [key, value] of Object.entries(sampleDataSet)) {
  console.log("Hello "  + value.firstName + " " + value.lastName);
}

Answer 2

database.ref("collection").once("value").then((snapshot) => { snapshot.forEach((userSnap) => { console.log('hello ' + userSnap.child(`firstName`).val() + ' ' + userSnap.child(`lastName`).val() ); }); });