Javascript :: .forEach #js

.Foreach1.js

let bridges = ['Brooklyn', 'Golden Gate', 'London'];

function logUpperCase(string) {
    console.log(string.toUpperCase());
}

bridges.forEach(logUpperCase);

// example 1
function whosASpecial(anArrOfPets) {
  let petString = '';
  
  anArrOfPets.forEach((pet, i) => {
    petString += `${pet.name} the ${pet.species} is very special!`;
    
    if (i !== anArrOfPets.length -1) petString += ' ';
  })
  return petString;
}

// example 1 deconstructed
function whosASpecial(anArrOfPets) {
  let petString = '';
  
  anArrOfPets.forEach(({name, species}, i) => {                     // deconstructing pet into name, species
    petString += `${name} the ${species} is very special!`;         // now we dont need pet.
    
    if (i !== anArrOfPets.length -1) petString += ' ';
  })
  return petString;
}

// this:
function myForEach(anArr, callback) {
  let done = anArr.forEach(callback);
  return done;
}
// does the same thing as this:
function myForEach(anArr, callback) {
  for (let i=0; i< anArr.length; i++) {
    let currElem = anArr[i];
    callback(currElem, i, anArr);
  }
}