Lesson13-MoreFunctions.md

Lesson

Prior Homework assessment

Lesson objectives

• Function declarations vs function expressions
• Arrow functions
• Self invoking functions
• Function hoisting function declarions

Lesson time to deliever:

Unknown...

Teacher instruction

We'll be covering some things they already know. So as much as possible ask them if they already know it and if they do get them to explain:

• E.g. What are two ways to write function (don't care about names, want code), get them to come up and write the code.
• Then tell them the names of the two ways
• Then ask them the difference between 2
• Then describe the difference.
• Then reinforce using the infographic
• Tie it all together

Explain why call back functions really important: Show examples in js e.g. map, foreach ...

Course materials

Lesson Plan: https://github.com/emarkexe2001/Web-Development-Course/blob/main/Week%20Nine/README.md

Tying it all together

function forEach(arr, fn){
  for(let i =0; i<arr.length; i++){
    fn(arr[i]);
  }
}

Additional course materials that teachers should review and can be used

• Infographic on lesson plan
• https://javascript.info/function-expressions - For function expressions
• https://javascript.info/arrow-functions-basics - For arrow functions
• https://stackoverflow.com/questions/336859/var-functionname-function-vs-function-functionname

Recommendations

• Additional notes

Homework

• You will create some very useful js libary funtions: We've done foreach for you
• filter

// Your code
var youngsters = filterIt(peopleArrary, function (item) {
	return item.age < 30;
});

// Must match
var expected = peopleArray.filter(function (item) {
	return item.age < 30;
});

• map

// Your code
var names = mapIt(peopleArray, (item) => return item.name);

// Must match
const expected = peopleArray.map((item) => return item.name; );

• some

// Your code
var names = hasSome(peopleArray, (item) => return item.age < 30);

// Must match

var anyUnder30 = peopleArray.some(function (item) {
	return  item.age < 30;
});