JavaScript

Variables

get type of variable

var $data = "blah";console.log($.type($data));

print variable in a string (backtick)

console.log(`this is my ${variable}`);

variable types

let myLet = "some var that can change later";const myConst = "constant value that wont change";

Arrays

add to array

const myArray = ["apple", "banana"];myArray.push("watermelon");

remove from array

const index = myArray.indexOf("banana");if (index > -1) { // only remove item if element is found myArray.splice(index, 1); // 2nd param means to remove 1 item only}

loop over array elements

myArray.forEach(element) => { console.log(element);}

get size of array

var size = arr.length;

Conditionals

Hashes

If /Else

let cheese = 'Cheddar';

if (cheese == 'Cheddar') {

console.log('this is cheddar');

} else if (cheese == 'Swiss') {

console.log('This is Swiss');

} else {

console.log('no cheese');

}

Logical Operators

&& = AND

|| = OR // if (name == 'frank' || name == 'bob')

! = NOT // if ( ! (name == 'frank' || name == 'bob'))

JQUERY

Parse through Select field option values

$.map($('#sel_customer option'), function(option){

if (option.value === "myOption") {

console.log("myOption is in options")

}

});

get array of <div> IDs from any <div> with class of "myclass"

<button onclick="getIDs('myclass')"> click me </button>

<script>function getIDs(selector) { const elements = document.querySelectorAll('div.'+selector);
const ids = Array.from(elements).map(element => element.id); return ids.join(','); // convert array to string}
</script>