JavaScript Arrays and Associate Arrays

JavaScript Arrays:

Reference:

W3 School JS

https://www.w3schools.com/js/js_arrays.asp

W3 School React JS

https://www.w3schools.com/react/default.asp

Example 1:

const cars = [
  "Saab",
  "Volvo",
  "BMW"
];  

Example 2:

const cars = [];
cars[0]= "Saab";
cars[1]= "Volvo";
cars[2]= "BMW"; 

or 

let  cars = []; //variables defined with let/const cannot be Redeclared.

//Variables defined with let/const have Block Scope.

for example 

{
  let x = 2;
}
// x can NOT be used outside the scope

or

var  cars = [];

JavaScript  Associate Arrays/object

Reference:

https://flexiple.com/associative-array-javascript/ 

Example 1:

var arr = {key1:'value1', key2:'value2'};

access object properties:

arr.key1 or arr['key1'] 

Example 2:

var arr = {
    "Company Name": 'Flexiple',
    "ID": 123
};
for (var key in arr) {
    var value = arr[key];
    document.write(key + " = " + value + '
');
}
//Output: 
Company Name = Flexiple
ID = 123