var vs no var

iteration.js

// if you open your chrome dev tools
// you'll see it log out the performance
// of each iterating in the console
var array = Array(100)

console.time("var")
for (i = 0; i < array.length; i++) {
  var e = array[i]

  for (j = 0; j < array.length; j++) {
    
    var e2 = array[j]
    
    for (k = 0; k < array.length; k++) {
      e * e2 * array[k]
    }
  }
}
console.timeEnd("var")

console.time("no var")
for (i = 0; i < array.length; i++) {
  
  for (j = 0; j < array.length; j++) {    
   
    for (k = 0; k < array.length; k++) {
      array[i] * array[j] * array[k]
    }
  }
} 
console.timeEnd("no var")