JavaScript(9)---Iterators

Itnerators

Notice the different methods being called on the arrays:

• .forEach()will execute the same code for each element of an array but does not change the array and returns undefined.

EX: 

Print:

I want to eat mango

I want to eat papaya

I want to eat pineapple

I want to eat apple

• .map()takes an argument of a callback function and returns a new array.

EX:

Print:

HelloWorld

[ 1, 2, 3, 4, 5]

• .filter() returns an array of elements after filtering out certain elements from the original array.
• .findIndex() on an array will return the index of the first element that evaluates to true in the callback function.  It returns -1 if none of the elements in the array satisfies the condition.

EX: 

• .reduce()method returns a single value after iterating through the elements of an array, thereby reducing the array. EX: 
  

Prints: 

• The some() method tests whether at least one element in the array passes the test implemented by the provided function.

EX: 

Prints: True

• The filter() method creates a new array with all elements that pass the test implemented by the provided function.

EX: 

• The every() method tests whether all elements in the array pass the test implemented by the provided function.

EX: 

Prints: True

• The .reduce( ) take an array that contains multiple values and returns a single value.

What did I learn? 

I learned about a few more methods to test the elements to see if it passes or not. And I also found another website that teaches about coding, the https://developer.mozilla.org/en-US/ it has everything that a developer might need.

What I'll be doing tomorrow? 

OBJECTS in javaScript