codecademy-max.js

var array = [-3 , -6, -2, -56, -32, -5, -89, -32];

function max1(array) {
  var largest = array[0]; // start with the first item
  for (i = 1; i < array.length; i++) // changed i to start at 1, to avoid extra work
  if (array[i]  > largest) {
    largest = array[i];
  }
  
  return largest;
}

// For thought...

function max2(arr) { 
  
  // Arrays have a nifty method called "reduce" that take a
  // "accumulator" function and (optionally) an initial value.
  // The accumulator takes two inputs and returns an accumulated
  // value. The accumulator is called for each value in the array
  // being given the previous accumulated value and the next item 
  // in the array. The first call to the accumulator is given the
  // initial value, or, if it is not supplied, the first item in 
  // the array
  return arr.reduce(function(a, b) { 
    
    // here I use the "terenary" operator ? :
    // The terenary operator is like an inline if statement:
    //     return cond ? a : b;
    // translates to:
    //    if (cond) { return a; } else { return b; }
    return a > b ? a : b; 
  }); 
}

// i.e., 

function max2(arr) { return arr.reduce(function(a, b) { return a > b ? a : b; }); }

// Funnily enough, Javascript already has a max function which 
// takes a list of values. i.e., Math.max(1, 2, 3) === 3
// One of the interesting things about Javascript is
// that we can invoke a function using an array as the
// parameters. We do this with the apply method on functions.

function max3(arr) { return Math.max.apply(null, arr); }