An exercise...
{% exercise %}
Define the isEven, getSquare and addToSum function expressions below to correctly build the res result set and sum variables.
{% initial %}
var data = [1,2,3,4,5,6,7,8,9,10],
isEven = /* TODO: filter function /,
getSquare = / TODO: map function /,
addToSum = / TODO: reduce function */,
res, sum;
res = data .filter(isEven) .map(getSquare);
sum = res.reduce(addToSum, 0);
{% solution %} var data = [1,2,3,4,5,6,7,8,9,10], isEven = function(n){ return n % 2 == 0; }, getSquare = function(n) { return n*n; }, addToSum = function(sum, n) { return sum += n; }, res, sum;
res = data .filter(isEven) .map(getSquare);
sum = res.reduce(addToSum, 0); {% validation %} assert(res.toString() == [4,16,36,64,100], sum == 220); {% context %} // This is context code available everywhere // The user will be able to call magicFunc in his code function magicFunc() { return 3; } {% endexercise %}