View source for JavaScript/CheatSheet

== Data Types ==
<pre>
var num = 8;                               // number
var strg = "Joe";                          // string
var vobj = {first: "John", last:"Doe"};    // object
var booli = false;                         // boolean
var arr = ["HTML","CSS","JS"];             // array
var a; typeof a;                           // undefined
var a = null;                              // value null

const pi = 3.14;

typeof strg                                // =string
</pre>

== Arrays ==
<pre>
var title = new Array();
title[0] = "Mr.";
title[1] = "Mrs.";
</pre>

<pre>
concat()
filter()
forEach()
join()
map()
pop()
push()
reduce()
reverse()
shift()
slice()
splice()
sort()
</pre>

== Strings ==
<pre>
charAt()
charCodeAt()
concat()
fromCharCode()
indexOf()
lastIndexOf()
match()
replace()              zpl = zpl.replace("1234567890",msg.serialnumber)
search()
slice()                checksum = String(sum).slice(-1)  # get last digit
split() 
substr()
substring()
toLowerCase()
toUpperCase()
valueOf()

includes()             if (string.includes(".prn")) {}
</pre>

== Conversions ==
<pre>
string = integer.toString()

integer = parseInt(string) + 1
</pre>

== leading zeros ==
<pre>
var string = "000000" + integer.toString()
string = string.substr(string.length-6)
</pre>

== Functions ==
<pre>
function addition(number1, number2) {
  return number1 + number2;
}


var person = {
    name: 'Peter',
    getName: function () {
        return this.name;
    }
}

person.getName()
</pre>

== Operators ==
<pre>
+           Addition
-           Subtraction
*           Multiplication
/           Division
(...)       Grouping operator, operations within brackets are executed earlier than those outside
%           Modulus (remainder )
++          Increment numbers
--          Decrement numbers

==          Equal to
===         Equal value and equal type
!=          Not equal
!==         Not equal value or not equal type
>           Greater than
<           Less than
>=          Greater than or equal to
<=          Less than or equal to
?           Ternary operator

&&          Logical and
||          Logical or
!           Logical not

&           AND statement
|           OR statement
~           NOT
^           XOR
<<          Left shift
>>          Right shift
>>>         Zero fill right shift
</pre>


== if - else ==
<pre>
if (condition) {
    // if condition is met
} else {
    // if condition is not met
}
</pre>

== switch ==
<pre>
switch(var) {
  case 1:
    // code 
    break;
  case 2:
    // code
    break;
  default:
    // code
} 
</pre>

== Loops ==
<pre>
for (var i = 0; i < 10; i++){
}

while (i < 10) {
  i++;
}

do {
  i++;
} while (i < 10);

break
continue
</pre>

== Escape Characters ==
<pre>
\'      Single quote
\"      Double quote

\\      Backslash
\b      Backspace
\f      Form feed
\n      New line
\r      Carriage return
\t      Horizontal tabulator
\v      Vertical tabulator
</pre>

== Dates & Times ==
<pre>
d = new Date();
var year = d.getFullYear();
var month = d.getMonth() + 1;
</pre>

<pre>
function ISO8601_week_no() 
  {
     dt = new Date(); 
     var tdt = new Date(dt.valueOf());
     var dayn = (dt.getDay() + 6) % 7;
     tdt.setDate(tdt.getDate() - dayn + 3);
     var firstThursday = tdt.valueOf();
     tdt.setMonth(0, 1);
     if (tdt.getDay() !== 4) 
       {
      tdt.setMonth(0, 1 + ((4 - tdt.getDay()) + 7) % 7);
        }
     return 1 + Math.ceil((firstThursday - tdt) / 604800000);
  }
</pre>

= Node-Red =
== Global variables ==
<pre>
var labelmode = global.get("labelmode")
</pre>

== Node Status ==
<pre>
node.status({fill:"gray",shape:"dot",text:msg.serialnumber + " = " + msg.pclass + "W"});
</pre>


== Stop messages ==
<pre>
if ( ...)) { 
return null; 
} else {
return msg;
}
</pre>

== InfluxDB ==
* write data with custom timestamp
<pre>
var timestamp = new Date(date + 'Z').getTime() * 1e6

msg = { payload : { value: value,
                    time: timestamp },
        measurement: topic }
</pre>