TO REMIND ME OF BASIC SYNTAX IN THE 2 LANGS:
Javascript (JS), and PHP

(PHP ESSENTIAL)
<?php statement; ?>  OR    <?= value?>
	The latter needs no echo, no semicolon. 
	The value is then translated into a print string and echo-ed out.


	**VARS
#PHP
$var1  case sensitive.  BUT functions are case INsensitive.
Always local unless otherwise labelled i.e. do "global $var1" inside each fn
Can use globals in functions AND set them there: like static vars.
global ${$varname};  $currentval = ${$varname};
Also: $$a or ${$a} gets the string in $a and de-refs it to use it as the varname

Vars can NOT be init in the decl.

#JS
var1.    Case sensitive, including functions?
Always global unless decl. locally.  So keep doing "var var1;" inside each fn.
var count = 0, unset=1, prevDisp=0;

More exactly, vars and I think fn-args are textually scoped to the nearest
enclosing fn-def else global.
Games/features with closures ensue.

Fn-args are call by name or ref. depending on whether the object is primitive
or an object (in which case a ptr is passed, so call-by-ref is the effect).

	**DOT NOTATION
#PHP
Dot operator is string concat.

#JS
+ operator is string concat. 
Dot in JS is object fields/properties NOT fn-exec.
NOT:  a.b.fn() is NOT fn(b(a));  
BUT:
(a.b ==== a["b"] );
var name = 'b';  then a.b ==== a[name];

	**ECHO
#PHP
echo is not a fn so can do either echo('asdf') or echo 'adsf';
echo 'asdf' . 'qr';
echo('asdf' . 'qr');
echo 'asdf', 'qr';  but not mulitple args AND parens.

#JS
No echo in JS; nearest is:    document.write('Hello World!');
	or alert(str); 

---==========================================================

	**IF conditionals
#PHP
if ($b) $a = 1;
$a = ($x > 0 ? 1 : 0); [Allowed]
$b AND $a=1;

if ($b) a = 1;
elseif ($b2) b=2;
else c=3;

if ($b):
	$a = 1;
	$a2 = 11;
elseif ($b2):
	$b=2;
else:
	$c=3;
endif;

#JS
if (b) a = 1;
a = (b > 0) ? 1 : 0; [Allowed]
y = (on) ? '' : 'none'; [Allowed]
	The condition can be just on,  (on), or (on==1)
	BUT only (on == 1) may work if type conversions from string are
	needed. (or else, use Number(on))

b && dothis();  N.B. JS returns the value of expr-part, not a boolean.
N.B. with the expr. you apparently CAN'T use parens to clarify, but can go on
and on with multiple exprs, like if-then-elseif-then-elseif....

if (b) a = 1;
else if (b2) b=2;
else c=3;

if (b) { x; y; z; }
else {a; b; c; }

	**LOOPS while, etc.
#PHP
while ($b) { ... break/continue };     do { } while ($b);

#JS
while (b) { ... break/continue };     do { } while (b);

	**forLOOPS
#PHP
for ($i=0; $i<=10; $i++)

#JS
for (var i=0; i<=10; i++) N.B. var anywhere in a func decls it as local; and
		re-decls hae no effect; nor does order within the function.

	**FOREACH
#PHP
foreach ($arr as $val) {} // when no, or implicit, index/keys
foreach ($GLOBALS as $key => $val) { echo "$key => $val <BR>"; };

// for sorting array
$myorder = array_keys($arr);
natcasesort($myorder);
foreach ($myorder as $key) { $p = mktypegen($arr[$key], $key); };

#JS
There is no 'foreach' keyword.
for (var i = 0; i < arr.length; i++) { out = a[$i]; };
for (var key in object) {}

There is a forEach function, but not worth it:
var groups = ['agenda', 'mysmall']; // list of groups to init
groups.forEach(function (gr1) {
	var = sessionStorage.getItem(gr1);
	expand(gr1, val);
});

Just using function calls is simpler?: and writing a fn which you have to
	do anyway in other forEach model.

function doPerclass(oneclass) {
	var val = sessionStorage.getItem(oneclass);
	expand(oneclass, val);
};
doPerclass('agenda');
doPerclass('mysmall');
  ...

JSON objects:   alert(JSON.stringify(data, null, 4));  

---==========================================================

	**ARRAYs
#PHP
Arrays are assoc, or 'maps'.
$arr = array( k1 => v1, k2 => k2);
$arr = [ k1 => v1, k2 => k2];

#JS
Arrays are lists. 
	(But as objects, you can add sub-objects that behave like assocArrays).
var arr = [] to decl/init it as arr;  arr.length=0 to re-zero it.
var arr = [3, 2, 'asdf']; inits it.
for (i=0; i<arr.length;  i++) myfn(arr[i]);  NOT for (i in arr);
for (i = 0; i < arr1.length; i++) {
	if (arr1[i].type == "text") { arr2.push(arr1[i]); }; };
	PUSH() to add elements to an array.


	**FUNCTION DECLS
#PHP
function fname($var1, $var2) {
	$gvar = 33;
	return $gvar;
}
For varargs, prepack args into an array and pass that in.
But can also use (inside the fn) func_num_args();, func_get_arg(1)
		or func_get_args() to get them.

#JS
function fname(var1, var2) {
	var localvar;
	var var1 =  arguments[0]; // redundant but what you get if decl as ()
	if (var1)  { ptr.innerHTML = var1; };
		// Test is false if var1 undefined in the fn-call.
	return gvar;
}
All fns are varargs.  Can access args inside fn via arguments[]
All fns return a value: <undefined> if not spec.



	**COMMENTS, SEMI-COLONS,  QUOTES
#PHP
// comment
# comment
/* also comment text, and across lines
*/
Semicolons: mostly required (except at end of ?> )
$str = 'x
        yz'; // no var expansion, may include LFs.
$str = "Here is \$var: $var \n";  [?? check this]
//Nowdoc facility, like in csh: uses quote type to ctrl the processing if any
	inside.
$x = <<<'LABEL'
any old text
LABEL

#JS
// comment
/*
	also comment text
*/
Either <LF> or ';' end a statement.
Single and double quotes mean the same; so can use one to quote the other;
	esp. e.g. when string contains something to go into another lang.


	**STRING edits
#PHP
$url = preg_replace('|[^/]$|', '${0}Y', $url);
	Always does global replace, unless arg4 sets nmb of replaces.
$out = str_replace('TGT', $replaceStr, $orig, $nmbDone);  no REs.
	If used, arg4 must be var, and receives a count of replacements.
	To limit nmb of replaces within a string, must use preg_replace
	OR could use truncate instead.

Truncate
$rest = substr("abcdef", -3, 1) -3 means 3rd back from last char.
$rest = substr($buf, $start, $len) Start at var2, delete Len chars
$rest = substr($buf, 2, 999) Start at char 2, keep all the rest.

#JS
picPtr.src = picPtr.src.replace(',', '');   Not global but first occurrence
	OR picPtr.src = picPtr.src.replace(/,/g, '');
	i.e. it takes either a string OR an RE as arg1
if (/,/.test(str)) { DOES work

	REGEXPs
#PHP
#JS
Can create REs by either/or:
var re = new RegExp(string + 'literalStr');
var re = /Any string\b/i;
		//which lets you put literal with meta-chars, but not vars.

Where var group = 'group33'; and should be appended by metachar \b ...
re1 = /group33\b/i;
re2 = new RegExp(group + '\\b'); 
re3 = new RegExp(group + /\b/.source);

and RE used: if (re2.test(ruletxt)) where ruletxt is a string var.

	**STRING cmps
#PHP
$s1 == $s2   equal after type conversions
$s1 === $s2   equal and same type 
== === != <> !== < >=   all work.
Strings are converted to numbers if necessary or appropriate. E.g. "10" == "1e1"
if (preg_match('/,del/', $f))  continue;  // so more cmps of strings ...
if (preg_match('/^\d{4}$/', $id) == 0) // If doesn't match then ...
if (preg_match('/^[a-z]+$/i', $id) == 0) // If doesn't match alpha, then ...
$new = str_replace($target, replace, $orig, &$count); case-sensitive.
$new = str_ireplace($target, replace, $orig); case-insensitive.
	Can give arrays for multiple find/replace pairs.
	Only fixed strings.
	$count receives a value for nmb of replaces done.


$new = preg_replace(pat, replacement substr, orig, $limit = -1, $nmbChanged)
$new = preg_replace(pat, '${1}00, $3', $origbuf, $limit = -1, $nmbChanged)
	Returns null for error; unchanged orig if no match, changed if match.
	If $limit pos, then max nmb changes.
	I show use of replacements by subpatterns

preg_match(pat, orig, &$matches)
	returns 1 or 0: whether any match.
	$matches[0] the text of the match. [1] the first subpat, ...
$nmatches = preg_match_all(pat, orig, &$matches);
	gets all matches and puts them in array.
	$matches[1][3] has 4th match to 1st () sub-pat.  [0] is whole pat.
	flags change what goes where in the arrays.

#JS
Ditto?  Strings are objects (built-in).
OR only == if same object??
If you add a nmb and a string, it gives a string.
var n=str.match(/ain/gi);  Returns an array of matches
    Can test for match with simple if:
    if (!   /,/.test(str)) { DOES work: both the expr AND with the bool negation
    if (picPtr.src.match(/,/)) DOESN'T work
    var regex = new RegExp(myconstant);
    string.replace(regex, "replacement");
    if (! regex.test(str)) {

    var str2=str.replace("Microsoft","W3Schools");
    http://www.w3schools.com/jsref/jsref_obj_string.asp  DOC for string fns
    http://www.w3schools.com/jsref/jsref_obj_regexp.asp

	**PTR UNDEF TESTS
#PHP
empty($x) true if either not there or false (or zero integer)
isset($x) false if either not there or set to null.
is_null($x) true if not set to anything (except null).
defined($x) constant is defined.  Only for constants, it says.

#JS
	Objects are null; vars/props are undefined.
	Vars (& attributes) that have not been assigned a val,
		are of type undefined.
if (typeof var1 === 'undefined') not decl. (but null).
if (obj.prop === undefined)  has never been assigned a val. [triple ===]
if (obj.prop)  To test it's decl, and assigned, and non-zero/false
var hasProperty = !!obj.prop;  This creates a bool from ptr.
if (isNaN(obj.colSpan)) tests that the var/attribute is: not undefined and is a
	number (as opposed to some other, or null, or empty value). 

To delete properties:
	delete myObject.keyname; or delete myObject["keyname"];
	http://perfectionkills.com/understanding-delete/
but cannot delete variables decl. as var x; nor functions.

	** TYPE AND NUMBER CONVERSIONS
#PHP
intval($var), floatval($var),   (int) "123";
strval($var)  But use sprintf() to control formatting.

#JS
var n = parseInt(str); parseFloat()    // if (isNaN(n))..
var n = Number(str);     // if (isNaN(n))..

var str = n.toString();
var str2 =  'opacity: 0.' + n.toString() + ';');

var marginpc = Math.round((100 - widthpc) / 4);


	** 	URL OBJECTS AND FS
#PHP
xxx

#JS
window.location.href gets full URL of current page/window.
document.URL; does same but may not work in Firefox

document.getElementById("aaa").getAttribute("href");
	Gets text as set in the 'href' field of, say, an <A > element.
window.location gets url as a whole object, ready-parsed into URL parts
	(see below).

For current page, window.location gets a "location object", with ready-defined
parts: hash(part after #), host (includes port), hostname, href (whole thing),
	origin, pathname, port, protocol, search (part after?).

Can set the location by setting the href field even if it is a partial /
relative URL.

Parsing function, given a whole URL:  
1) if possible, use location object's pre-parsing.
2) DIY using split() var pathArray = window.location.pathname.split( '/' );

To get an abs URL out of a relative one, here's code I haven't tested.
It defines a function then calls it.
var getAbsoluteUrl = (function() {
	var a;
	return function(url) {
		if(!a) a = document.createElement('a');
		a.href = url;
		return a.href;
	};
})();