egghead-redux-course-flash-cards.json

[
    {
        "slug": "react-redux-the-single-immutable-state-tree",
        "question": "What is the *entire* state of the application represented as?",
        "answer": "A single Javascript object."
    },
    {
        "slug": "react-redux-describing-state-changes-with-actions",
        "question": "What is an action?",
        "answer": "A minimally represented change of the state"
    },
    {
        "slug": "react-redux-pure-and-impure-functions",
        "question": "What is a pure function? ",
        "answer": "A function where the only data it receives is what you pass in, and it always returns a new value that mutates nothing. \nIt does not make network requests or any other form of side effect."
    },
    {
        "slug": "javascript-redux-the-reducer-function",
        "question": "What do mutations of your application state need to be described by?",
        "answer": "A pure function, known as a *reducer*, that takes the previous state object, an action object, and returns the next state of your application"
    },
    {
        "slug": "react-redux-writing-a-counter-reducer-with-tests",
        "question": "If your reducer receives an *undefined* state what should you return",
        "answer": "If the state is undefined, return the initial state."
    },
    {
        "slug": "react-redux-store-methods-getstate-dispatch-and-subscribe",
        "question": "How do you define a new Redux store?",
        "answer": "`const storeName = createStore(reducerName);`"
    },
    {
        "slug": "react-redux-implementing-store-from-scratch",
        "question": "What method allows you to dispatch actions to the store?",
        "answer": "`storeName.dispatch('ACTION_NAME');`"
    },
    {
        "slug": "react-redux-react-counter-example",
        "question": "How do you subscribe to a react component? ",
        "answer": "You can define a component and then call it within a method. \nYou can then `.subscribe()` to said method."
    },
    {
        "slug": "react-redux-avoiding-array-mutations-with-concat-slice-and-spread",
        "question": "What is a mutation?",
        "answer": "When the original data is modified in some way, as opposed to creating new data."
    },
    {
        "slug": "react-redux-avoiding-object-mutations-with-object-assign-and-spread",
        "question": "How do you update an object without mutating the original?",
        "answer": "You call `Object.assign()` with an empty object, the old object, and the property that you wish to update."
    },
    {
        "slug": "react-redux-writing-a-todo-list-reducer-adding-a-todo",
        "question": "In the reducer, how do you handle incoming actions?",
        "answer": "Via a `switch` statement that takes the `.type` off of the incoming action."
    },
    {
        "slug": "react-redux-writing-a-todo-list-reducer-toggling-a-todo",
        "question": "How do you change the state when there are multiple items within the state?",
        "answer": "You can iterate over the array using `.map()`, at it returns a new array as opposed to mutating the original state. \nRemember to still `return` items that you would still wish to keep in the state!"
    },
    {
        "slug": "react-redux-reducer-composition-with-arrays",
        "question": "What is *Reducer Composition*? ",
        "answer": "It is when you call to other reducers within a parent reducer."
    },
    {
        "slug": "react-redux-reducer-composition-with-objects",
        "question": "How can we store new information without changing existing reducers?",
        "answer": "We can use reducer composition to call existing reducers within a new reducer, and combine the parts into a state object."
    },
    {
        "slug": "react-redux-reducer-composition-with-combinereducers",
        "question": "What do we pass into the `combineReducers()` method?",
        "answer": "An object of `stateField: Reducer` key/value pairs."
    },
    {
        "slug": "javascript-redux-implementing-combinereducers-from-scratch",
        "question": "In redux, what is an important concept of functional programming that you should always remember?",
        "answer": "That functions can be passed other functions as arguments and can return functions."
    },
    {
        "slug": "react-redux-react-todo-list-example-adding-a-todo",
        "question": "What is a *root reducer*?",
        "answer": "The reducer you create the store with"
    },
    {
        "slug": "react-redux-react-todo-list-example-toggling-a-todo",
        "question": "",
        "answer": ""
    },
    {
        "slug": "react-redux-react-todo-list-example-filtering-todos",
        "question": "How do you write a component that can change the application state?",
        "answer": "1. Write a component that is capable of event handling \n2. Render the component to the DOM, passing an action type as a prop. \n3. Write a reducer to handle said action"
    },
    {
        "slug": "react-redux-extracting-presentational-components-todo-todolist",
        "question": "What is a presentational component?",
        "answer": "Components that are only concerned with presenting in the DOM."
    },
    {
        "slug": "react-redux-extracting-presentational-components-addtodo-footer-filterlink",
        "question": "How do you move functionality outside of a presentational component?",
        "answer": "By replacing it with a named prop that you can pass the functionality to when calling the component."
    },
    {
        "slug": "react-redux-extracting-container-components-filterlink",
        "question": "How do you avoid passing props down all the way from the top down to your presentational components?",
        "answer": "By moving functionality passed down from top level components into a self contained *Container Component* that is capable of reading from the store's state."
    },
    {
        "slug": "react-redux-extracting-container-components-visibletodolist-addtodo",
        "question": "What is the job of a container component?",
        "answer": "To connect a presentational component to the store and specify the data and the behavior that it needs."
    },
    {
        "slug": "react-redux-passing-the-store-down-explicitly-via-props",
        "question": "Why wouldn't you want to have a global reference to the store in a real application?",
        "answer": "Having a global reference to the store would make you application much harder to test, you may want to test your code with different mock stores."
    },
    {
        "slug": "react-redux-passing-the-store-down-implicitly-via-context",
        "question": "What method allows you to pass a context down to all of the component's children and grandchildren?",
        "answer": "`childContextTypes`"
    },
    {
        "slug": "react-redux-passing-the-store-down-with-provider-from-react-redux",
        "question": "What library provides you with a `<Provider>` component?",
        "answer": "ReactRedux"
    },
    {
        "slug": "react-redux-generating-containers-with-connect-from-react-redux-visibletodolist",
        "question": "How do you write a container component using the `connect` method?",
        "answer": "You write two functions, one that returns an object with the props that depend on the redux store, and another that returns a dispatch method. \n\nThen define a function that calls `connect()` with the two functions you just wrote. Call a second time to `connect` with the presentational component passed in, since it is a curried function. Example: \n\n`const funcName = connect(mapeStateToProps, mapDispatchToProps)(PresentationComponent)`"
    },
    {
        "slug": "react-redux-generating-containers-with-connect-from-react-redux-addtodo",
        "question": "What is the default behavior if you leave the `mapDispatchToProps` argument in `connect` empty?",
        "answer": "It will just inject the `dispatch` function as a prop!"
    },
    {
        "slug": "react-redux-generating-containers-with-connect-from-react-redux-footerlink",
        "question": "How do you get access to the container component's props when you are using the `connect` pattern?",
        "answer": "As a second argument to `mapStateToProps` and `mapDispatchToProps` you can declare a variable that has access to the container's props."
    },
    {
        "slug": "react-redux-extracting-action-creators",
        "question": "What is an action creator?",
        "answer": "It is a function that composes an action. They are more maintainable than writing actions inline."
    }
]