dengjonathan

var React = require('react');
var PropTypes = React.PropTypes;
var styles = require('../styles');
var Link = require('react-router').Link
var UserDetails = require('../components/UserDetails');
var UserDetailsWrapper = require('../components/UserDetailsWrapper');

function puke(object) {
  return <pre>{JSON.stringify(object, null, ' ')}</pre>;
}

dengjonathan

import React from "react";
import { render } from "react-dom";

const ParentComponent = React.createClass({
  getDefaultProps: function() {
    console.log("ParentComponent - getDefaultProps");
  },
  getInitialState: function() {
    console.log("ParentComponent - getInitialState");
    return { text: "" };

dengjonathan

names2 = ['kendra', 'kim', 'kampbell'];

// use this as your callback function in map
var capitalize = function(word) {
  return word[0].toUpperCase() + word.slice(1);
};

// we need each implemented for map to work
var each = function(array, callback) {
  for (var i = 0; i < array.length; i++) {

dengjonathan

var d = 'not modified';

// add is a pure function that doesn't modify anything out of its scope
function add(x, y) {
  return x + y;
}

add(2, 3) // 5
add(2, 3) // always gonna be 5
console.log(d) // 'not modified'

dengjonathan

names2 = ['kendra', 'kim', 'kampbell'];

var capitalize = function(word) {
  return word[0].toUpperCase() + word.slice(1);
};

map(names, capitalize); // ['Kendra', 'Kim', 'Kampbell']

dengjonathan

names2 = ['kendra', 'kim', 'kampbell'];

// use this as your callback function in map
var capitalize = function(word) {
  return word[0].toUpperCase() + word.slice(1);
};

// we need each implemented for map to work
var each = function(array, callback) {
  for (var i = 0; i < array.length; i++) {

dengjonathan

var i;
var names = ['jon', 'jane', 'jack'];

// imperative programming
for (i = 0; i < names.length; i++) {
  names[i] = names[i][0].toUpperCase() + names[i].slice(1);
}

console.log(names) // ['Jon', 'Jane', 'Jack']
console.log(i) // 3

dengjonathan

var i;
var names = ['jon', 'jane', 'jack'];

// imperative programming
for (i = 0; i < names.length; i++) {
  names[i] = names[i][0].toUpperCase() + names[i].slice(1);
}

console.log(names) // ['Jon', 'Jane', 'Jack']
console.log(i) // 3

dengjonathan

// this is better
function plusOne(number) {
  return number++;
}
plusOne(5); // 6

// this is worse
var number = 5;

function plusOne() {

dengjonathan

/* how do you encapsulate a for loop within a function
so that each(names, callback) will do the same thing as the for loop? */

// ensure that the all inputs are explicity declared in function signature
var each = function(array, callback) {
  for (var i = 0; i < array.length; i++) {
    callback(array[i]);
  }
};