index.js

// Variable declaration
var animalsVectorArray = [];
var arraySize = 10; // arbitrary array size
var randomPlaceForTheCat = Math.floor(Math.random() * arraySize)-1;

console.log('Our cat will be on the: ' + randomPlaceForTheCat + 'index.');

// Generate random values for the `animalsVectorArray` based on the `possibleAnimals`
for (var i=0; i<arraySize; i++) {
  if (i===randomPlaceForTheCat) {
    animalsVectorArray[i] = 'cat';
  } else {
    animalsVectorArray[i] = 'mouse';
  }
}

console.log('Our `animalsVectorArray` looks like this:', JSON.stringify(animalsVectorArray)); // JSON.stringify does something really cool, can you figure it out?, try passing an object like {name:'omega',power:9000}

console.log('Looking for the cat...');

for (var i=0; i<arraySize; i++) {
  if (animalsVectorArray[i] === 'cat') {
    console.log('Found the cat!  in the index:', i);
    break; // breaks a for loop :)
  } else {
    console.log('Damn sorry, this is just a mouse');
  }
}