The- Example:Math
contains properties and methods for constants and mathematical operations.
TheMath
object is applied directly, followed by property or method.
const x = Math.PI; //value of PI var y = Math.sqrt(16); //square root of 16
<script> //returns a random number between min and max (inclusive) function randomInt(min, max){ min = Math.ceil(min); max = Math.floor(max); return Math.floor(Math.random() *(max - min + 1)) +min; } var nr1 = randomInt(1, 10); //number between 1 and 10 var nr2 = randomInt(-10, 20); //number between -10 and 20 document.write('<br> Random number between 1 and 10: '+ nr1 +'<br> Random number between -10 and 20: '+ nr2); </script>
The Math object can be extended, you can add custom properties and methods using this syntax:
//defining property Math.prop_name = prop_val; //defining method Math.method_name = function(){ //code of method }
<script> //returns the greatest common divisor of a list of arguments Math.cmmdc = function() { if(arguments.length ==2){ if(arguments[1] ==0) return arguments[0]; else return Math.cmmdc(arguments[1], arguments[0] % arguments[1]); } else if(arguments.length >2){ var result = Math.cmmdc(arguments[0], arguments[1]); for(var i=2; i<arguments.length; i++) result = Math.cmmdc(result, arguments[i]); return result; } }; let mdv = Math.cmmdc(20, 30, 15, 70, 40); // 5 document.write('<br> The greatest common divisor of the numbers: (20, 30, 15, 70, 40) is: '+ mdv); </script>
Math
object properties represent mathematical constants.Math.E
- value of Euler’s constant (2.718)Math.LN2
- the natural logarithm of 2 (0.693)Math.LN10
- natural logarithm of 10 (2.303)Math.LOG2E
- base 2 logarithm of E (1.443)Math.LOG10E
- base 10 logarithm of E (0.434)Math.PI
- value of PI (3.14159)Math.SQRT1_2
- square root of 0.5 (0.707)Math.SQRT2
- square root of 2 (1.414)Math.abs(x)
- returns the absolute value of.var n1 = 18; var n2 = -25.3; console.log(Math.abs(n1)); // 18 console.log(Math.abs(n2)); // 25.3
Math.acos(x)
- returns the arccosine of x, in radians.var n1 = -1; var n2 = 0.5; console.log(Math.acos(n1)); // 3.141592653589793 console.log(Math.acos(n2)); // 1.0471975511965979
Math.asin(x)
- returns the arcsine of x, in radians.var n1 = -1; var n2 = 0.5; console.log(Math.asin(n1)); // -1.5707963267948966 (-pi/2) console.log(Math.asin(n2)); // 0.5235987755982989
Math.atan(x)
- the arctangent of x, in radians.var n1 = 1; var n2 = 0.5; console.log(Math.atan(n1)); // 0.7853981633974483 console.log(Math.atan(n2)); // 0.4636476090008061
Math.atan2(y, x)
- returns the arctangent of the quotient of its arguments (x,y).var v1 = Math.atan2(90, 15); var v2 = Math.atan2(15, 90); console.log(v1); // 1.4056476493802699 console.log(v2); // 0.16514867741462683
Math.cbrt(x)
- returns the cube root of a number.var n1 = 64; console.log(Math.cbrt(n1)); // 4
Math.ceil(x)
- returns the smallest integer greater than or equal to x.var n1 = 18.7; var n2 = -25.3; console.log(Math.ceil(n1)); // 19 console.log(Math.ceil(n2)); // -25
Math.cos(x)
- the cosine of the number x, in radians.var n1 = 0; var n2 = 1; console.log(Math.cos(n1)); // 1 console.log(Math.cos(n2)); // 0.5403023058681398
Math.exp(x)
- returns the value of E to the power of the x.var n1 = 2; var n2 = -1; console.log(Math.exp(n1)); // 7.38905609893065 console.log(Math.exp(n2)); // 0.36787944117144233
Math.floor(x)
- returns x, rounded downwards to the nearest integer.var n1 = 18.7; var n2 = -25.3; console.log(Math.floor(n1)); // 18 console.log(Math.floor(n2)); // -26
Math.hypot(x1, x2, ...)
- returns the square root of the sum of squares of its arguments x1, x2, ...var n1 = 3; var n2 = 4; console.log(Math.hypot(n1, n2)); // 5
Math.log(x)
- the natural logarithm of x.var n1 = 1; var n2 = 10; console.log(Math.log(n1)); // 0 console.log(Math.log(n2)); // 2.302585092994046
Math.log10(x)
- returns the base 10 logarithm of a number.var n1 = 100000; var n2 = 2; console.log(Math.log10(n1)); // 5 console.log(Math.log10(n2)); // 0.3010299956639812
Math.max(x1, x2, ...)
- returns the number with the highest value.var n1 = 61.5; var n2 = -65.3; var n3 = 53; console.log(Math.max(n1, n2, n3)); // 61.5
Math.min(x1, x2, ...)
- returns the number with the lowest value.var n1 = 61.5; var n2 = -65.3; var n3 = 53; console.log(Math.min(n1, n2, n3)); // -65.3
Math.pow(x, y)
- the value of 'x' raised to the power of 'y'.var x = 4; var y = 3; console.log(Math.pow(x, y)); // 64
Math.random()
- a random number between 0 and 1.document.write('<br> - Random number between 0 and 1: '+ Math.random());
Math.round(x)
- returns the value of the number x rounded to the nearest integer.var n1 = 5.8; var n2 = -25.38; console.log(Math.round(n1)); // 6 console.log(Math.round(n2)); // -25
Math.sin(x)
- the sine of x (x is in radians).var n1 = 0; var n2 = 1; var n3 = Math.PI /2; console.log(Math.sin(n1)); // 0 console.log(Math.sin(n2)); // 0.8414709848078965 console.log(Math.sin(n3)); // 1
Math.sqrt(x)
- returns the square root of x.var n1 = 4; var n2 = 81.25; console.log(Math.sqrt(n1)); // 2 console.log(Math.sqrt(n2)); // 9.013878188659973
Math.tan(x)
- the tangent of an angle x (x in radians).var n1 = 1; var n2 = 90; console.log(Math.tan(n1)); // 1.5574077246549023 console.log(Math.tan(n2)); // -1.995200412208242
Math.trunc(x)
- returns the integer part of the number x, removing decimals.var n1 = 18.78; var n2 = -25.3; console.log(Math.trunc(n1)); // 18 console.log(Math.trunc(n2)); // -25
<ul> <li>http://coursesweb.net/html/</li> <li>http://coursesweb.net/css/</li> </ul>
.some_class { display: list-item; }
var obj = { "courses": ["php", "javascript", "ajax"] }; var jsonstr = JSON.stringify(obj); alert(jsonstr); // {"courses":["php","javascript","ajax"]}
$strhtml = '<body><div id="dv1">CoursesWeb.net</div></body>'; $dochtml = new DOMDocument(); $dochtml->loadHTML($strhtml); $elm = $dochtml->getElementById("dv1"); echo $elm->nodeValue; // CoursesWeb.net