the power of dom utilities and selector engines

add-even-class.js

// the power of dom utilities and selector engines
// $('table.projects tr:even').addClass('even-row');

var slice = Array.prototype.slice,
    toArray = function (obj) {
      return Array.prototype.slice.call(obj, 0)
    }

var tables = toArray(document.querySelectorAll('table.projects'))

tables.forEach(function(tableEl) {
  var rows = toArray(tableEl.querySelectorAll('>tr'))
  rows.forEach(function(rowEl, i) {
    if (i%2)
      rows.classList.add('even-row')
  })
})