Javascript jak odeslat data z html stránky na server php

List of usefull JavaSript functions and constans

var 1_radian_to_degree = 180 / Math.PI; // 57,295779513082320876798154814105 degree
var 1_degree_to_radian = Math.PI / 180; // 0,01745329251994329576923690768489 radian
var 360_degree =  2 * Math.PI * 1_radian_to_degree;

parseInt("10.33") // returns 10 string to integer
parseFloat("10.33") // returns 10.33 string to float

// change sign
var a = -1;
a = a * -1; // +1
// random sign
a *= Math.floor(Math.random()*2) == 1 ? 1 : -1; 


var who_is = 58;
var type = (typeof who_is); // number

Math.E  // natural logarithms, e, approximately 2.718281828459045
Math.LN10 // natural logarithm of 10, approximately 2.302585092994046
Math.LN2 // natural logarithm of 2, approximately 0.6931471805599453
Math.PI // approximately 3.141592653589793
Math.SQRT1_2 // square root of 1/2 which is approximately 0.7071067811865476
Math.SQRT2 // square root of 2, approximately 1.4142135623730951
Math.pow(4, 2) = 16 // 4 x 4 ... base 4 to the exponent 2 power
Math.abs(-5) absolute value of a number // return 5

Math.tan(degrees * Math.PI / 180) // get tangent from degrees
Math.tan(degree * Math.PI / 180)*adjacent = opposite
opposite / Math.tan(degree * Math.PI / 180) = adjacent
Math.acos(adjacent / hypotenuse) // angle of a right-angle triangle in radians
Math.atan(opposite / adjacent) // angle of a right-angle triangle in radians
var adjacent = Math.cos(radian) * hypotenuse; // leng of adjacent side 
// find the point on a circle if you know the circle´s radius
var x = Math.cos(pointAngleInRadiansFromCentreOfCircle) * radius;
var y = Math.sin(pointAngleInRadiansFromCentreOfCircle) * radius;

Math.cbrt(64) //  cube root of a number 4 (4 x 4 x 4)
Math.exp(xNumber) // returns e<sup>xNumber</sup> ... e == Math.E 


Math.ceil() // always rounds a number up to the next largest integer
Math.ceil(1.001) // 2

Math.floor() // returns largest integer less than or equal to a given number
Math.floor(5.85) = 5
Math.floor(-5.15) = -6

const arrayA = [2, 3, 1];
Math.min(...arrayA) = 1;
Math.max(1, 3, 2) = 3;

Math.random() // returns 0.000.... - 0.99999999999
Math.random() * 3 // returns 0.000 - 2.99999999999

Math.round() // returns value of a number rounded to the nearest integer.
Math.round(0.9) // 1
Math.round(5.5) // 6
Math.round(5.05) // 5 

Math.floor(Math.random() * 3) // returns 0, 1, 2

Date: 14.06.2020 - 08:38

Jak naformátovat číslo například 1000 aby výstup byl 1 000.

How formatting Numbers in javascript

// in us return 1,000.00 in czech cz return 1 000,00
var newNumber = format_Of_Number ('cz', 1000.00); // cz is czech format - us is us format of number 


function format_Of_Number (stat, num) {
  stat = stat.toLowerCase();
	nStr = this + '';
	var x = nStr.split('.');
	var x1 = x[0];
	var x2;
	if(stat=='cz')
	x2 = x.length > 1 ? ',' + x[1] : ''; // nahradime tecku carkou
	else if(stat=='us')
	x2 = x.length > 1 ? '.' + x[1] : ''; // us format
	
	var rgx = /(d+)(d{3})/;
	while (rgx.test(x1)) {
		if(stat=='cz')
		x1 = x1.replace(rgx, '$1' + ' ' + '$2'); // nahradime mezerou cesky format 1 000,00
		else if(stat=='us')
		x1 = x1.replace(rgx, '$1' + ',' + '$2'); // us format 1,000.00
	}
	return x1 + x2;
}

Některé funkce pracující s polem v JavaScriptu

concat([item1[, item2[, . . . [, itemN]]]])
concat([string2[, string3[, . . . [, stringN]]]])
/* spoji stringy nebo pole a vraci novy string nebo pole */

join(separator)
/* vrati v string spojene itemy poli oddelene separatorem*/

push([item1 [item2 [. . . [itemN ]]]])
/* prida na konec pole novy item a vraci delku pole*/

pop()
/* odebere posledni element z pole a vrati jeho hodnotu*/

reverse()
/*vraci obracene poradi itemu pole*/

shift()
/* odebere prvni item z pole a vrati jej*/

slice(start, [end])
/* varaci cast pole*/
  var  numArray = new Array(3,2,5,9);
  var  newNumArray = numArray.slice(1,3); // 2,5



sort(sortFunction)
/* setridi pole */

splice(start, deleteCount, [item1[, item2[, . . . [,itemN]]]])
/* odebere element z pole, popripade vlozi novy a vrati odebrany element*/
    var numArray = new Array(3,2,5,9);
    var newNumArray = numArray.splice(1,1); // 3,5,9


unshift([item1[, item2 [, . . . [, itemN]]]])
/* prida na pocatek item, ktery je parametrem funkce  */
var myA = new Array(10,11,12); 
myA.unshift(1); // 1,10,11,12

Někdy potřebujeme získat url adresu pro menu, nebo odkazy atd.
pozor funkce je empty() a ne emptyempty

$currentURL = (!empty($_SERVER['HTTPS'])) 
? "https://".$_SERVER['SERVER_NAME'].$_SERVER['REQUEST_URI'] 
: "//".$_SERVER['SERVER_NAME'].$_SERVER['REQUEST_URI'];

php bývá vyčítano, že proměnné jsou typově nejednoznačné. To je sice pravda, ale php má funkci, která vrátí typ proměnné v dané části kodu.

$var = 10;   
// funkce  gettype vrací retezec s nazvem typu
// tak, jak jej vydi prekladac pri linkovani kodu  
$s = gettype($var); // $s == 'integer'   
  
$var = 'some text';   
$s = gettype($var); // $s == 'string'   
  
$var = 10.1;   
$s = gettype($var); // $s == 'double'