From 218934fa2ed1c702a6d3923d2aa2cc6b43c48684 Mon Sep 17 00:00:00 2001 From: Peter Bengtsson Date: Tue, 8 Dec 2020 14:43:23 -0500 Subject: initial commit --- .../reference/global_objects/math/index.html | 196 +++++++++++++++++++++ 1 file changed, 196 insertions(+) create mode 100644 files/vi/web/javascript/reference/global_objects/math/index.html (limited to 'files/vi/web/javascript/reference/global_objects/math/index.html') diff --git a/files/vi/web/javascript/reference/global_objects/math/index.html b/files/vi/web/javascript/reference/global_objects/math/index.html new file mode 100644 index 0000000000..bfaa405142 --- /dev/null +++ b/files/vi/web/javascript/reference/global_objects/math/index.html @@ -0,0 +1,196 @@ +--- +title: Math +slug: Web/JavaScript/Reference/Global_Objects/Math +tags: + - JavaScript + - Math + - NeedsTranslation + - Reference + - TopicStub +translation_of: Web/JavaScript/Reference/Global_Objects/Math +--- +
{{JSRef}}
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Math is a built-in object that has properties and methods for mathematical constants and functions. Not a function object.

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Description

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Unlike the other global objects, Math is not a constructor. All properties and methods of Math are static. You refer to the constant pi as Math.PI and you call the sine function as Math.sin(x), where x is the method's argument. Constants are defined with the full precision of real numbers in JavaScript.

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Properties

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{{jsxref("Math.E")}}
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Euler's constant and the base of natural logarithms, approximately 2.718.
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{{jsxref("Math.LN2")}}
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Natural logarithm of 2, approximately 0.693.
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{{jsxref("Math.LN10")}}
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Natural logarithm of 10, approximately 2.303.
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{{jsxref("Math.LOG2E")}}
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Base 2 logarithm of E, approximately 1.443.
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{{jsxref("Math.LOG10E")}}
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Base 10 logarithm of E, approximately 0.434.
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{{jsxref("Math.PI")}}
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Ratio of the circumference of a circle to its diameter, approximately 3.14159.
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{{jsxref("Math.SQRT1_2")}}
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Square root of 1/2; equivalently, 1 over the square root of 2, approximately 0.707.
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{{jsxref("Math.SQRT2")}}
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Square root of 2, approximately 1.414.
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Methods

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Note that the trigonometric functions (sin(), cos(), tan(), asin(), acos(), atan(), atan2()) expect or return angles in radians. To convert radians to degrees, divide by (Math.PI / 180), and multiply by this to convert the other way.

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Note that many math functions have a precision that's implementation-dependent. This means that different browsers can give a different result, and even the same JS engine on a different OS or architecture can give different results.

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{{jsxref("Global_Objects/Math/abs", "Math.abs(x)")}}
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Returns the absolute value of a number.
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{{jsxref("Global_Objects/Math/acos", "Math.acos(x)")}}
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Returns the arccosine of a number.
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{{jsxref("Global_Objects/Math/acosh", "Math.acosh(x)")}}
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Returns the hyperbolic arccosine of a number.
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{{jsxref("Global_Objects/Math/asin", "Math.asin(x)")}}
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Returns the arcsine of a number.
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{{jsxref("Global_Objects/Math/asinh", "Math.asinh(x)")}}
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Returns the hyperbolic arcsine of a number.
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{{jsxref("Global_Objects/Math/atan", "Math.atan(x)")}}
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Returns the arctangent of a number.
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{{jsxref("Global_Objects/Math/atanh", "Math.atanh(x)")}}
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Returns the hyperbolic arctangent of a number.
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{{jsxref("Global_Objects/Math/atan2", "Math.atan2(y, x)")}}
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Returns the arctangent of the quotient of its arguments.
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{{jsxref("Global_Objects/Math/cbrt", "Math.cbrt(x)")}}
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Returns the cube root of a number.
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{{jsxref("Global_Objects/Math/ceil", "Math.ceil(x)")}}
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Returns the smallest integer greater than or equal to a number.
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{{jsxref("Global_Objects/Math/clz32", "Math.clz32(x)")}}
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Returns the number of leading zeroes of a 32-bit integer.
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{{jsxref("Global_Objects/Math/cos", "Math.cos(x)")}}
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Returns the cosine of a number.
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{{jsxref("Global_Objects/Math/cosh", "Math.cosh(x)")}}
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Returns the hyperbolic cosine of a number.
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{{jsxref("Global_Objects/Math/exp", "Math.exp(x)")}}
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Returns Ex, where x is the argument, and E is Euler's constant (2.718…), the base of the natural logarithm.
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{{jsxref("Global_Objects/Math/expm1", "Math.expm1(x)")}}
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Returns subtracting 1 from exp(x).
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{{jsxref("Global_Objects/Math/floor", "Math.floor(x)")}}
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Returns the largest integer less than or equal to a number.
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{{jsxref("Global_Objects/Math/fround", "Math.fround(x)")}}
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Returns the nearest single precision float representation of a number.
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{{jsxref("Global_Objects/Math/hypot", "Math.hypot([x[, y[, …]]])")}}
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Returns the square root of the sum of squares of its arguments.
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{{jsxref("Global_Objects/Math/imul", "Math.imul(x, y)")}}
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Returns the result of a 32-bit integer multiplication.
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{{jsxref("Global_Objects/Math/log", "Math.log(x)")}}
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Returns the natural logarithm (loge, also ln) of a number.
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{{jsxref("Global_Objects/Math/log1p", "Math.log1p(x)")}}
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Returns the natural logarithm (loge, also ln) of 1 + x for a number x.
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{{jsxref("Global_Objects/Math/log10", "Math.log10(x)")}}
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Returns the base 10 logarithm of a number.
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{{jsxref("Global_Objects/Math/log2", "Math.log2(x)")}}
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Returns the base 2 logarithm of a number.
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{{jsxref("Global_Objects/Math/max", "Math.max([x[, y[, …]]])")}}
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Returns the largest of zero or more numbers.
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{{jsxref("Global_Objects/Math/min", "Math.min([x[, y[, …]]])")}}
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Returns the smallest of zero or more numbers.
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{{jsxref("Global_Objects/Math/pow", "Math.pow(x, y)")}}
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Returns base to the exponent power, that is, baseexponent.
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{{jsxref("Global_Objects/Math/random", "Math.random()")}}
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Returns a pseudo-random number between 0 and 1.
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{{jsxref("Global_Objects/Math/round", "Math.round(x)")}}
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Returns the value of a number rounded to the nearest integer.
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{{jsxref("Global_Objects/Math/sign", "Math.sign(x)")}}
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Returns the sign of the x, indicating whether x is positive, negative or zero.
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{{jsxref("Global_Objects/Math/sin", "Math.sin(x)")}}
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Returns the sine of a number.
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{{jsxref("Global_Objects/Math/sinh", "Math.sinh(x)")}}
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Returns the hyperbolic sine of a number.
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{{jsxref("Global_Objects/Math/sqrt", "Math.sqrt(x)")}}
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Returns the positive square root of a number.
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{{jsxref("Global_Objects/Math/tan", "Math.tan(x)")}}
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Returns the tangent of a number.
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{{jsxref("Global_Objects/Math/tanh", "Math.tanh(x)")}}
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Returns the hyperbolic tangent of a number.
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Math.toSource() {{non-standard_inline}}
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Returns the string "Math".
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{{jsxref("Global_Objects/Math/trunc", "Math.trunc(x)")}}
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Returns the integer part of the number x, removing any fractional digits.
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Extending the Math object

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As with most of the built-in objects in JavaScript, the Math object can be extended with custom properties and methods. To extend the Math object, you do not use prototype. Instead, you directly extend Math:

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Math.propName = propValue;
+Math.methodName = methodRef;
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For instance, the following example adds a method to the Math object for calculating the greatest common divisor of a list of arguments.

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/* Variadic function -- Returns the greatest common divisor of a list of arguments */
+Math.gcd = function() {
+    if (arguments.length == 2) {
+        if (arguments[1] == 0)
+            return arguments[0];
+        else
+            return Math.gcd(arguments[1], arguments[0] % arguments[1]);
+    } else if (arguments.length > 2) {
+        var result = Math.gcd(arguments[0], arguments[1]);
+        for (var i = 2; i < arguments.length; i++)
+            result = Math.gcd(result, arguments[i]);
+        return result;
+    }
+};
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Try it:

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console.log(Math.gcd(20, 30, 15, 70, 40)); // `5`
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Specifications

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SpecificationStatusComment
{{SpecName('ES1')}}{{Spec2('ES1')}}Initial definition. Implemented in JavaScript 1.1.
{{SpecName('ES5.1', '#sec-15.8', 'Math')}}{{Spec2('ES5.1')}} 
{{SpecName('ES6', '#sec-math-object', 'Math')}}{{Spec2('ES6')}}New methods {{jsxref("Math.log10()", "log10()")}}, {{jsxref("Math.log2()", "log2()")}}, {{jsxref("Math.log1p()", "log1p()")}}, {{jsxref("Math.expm1()", "expm1()")}}, {{jsxref("Math.cosh()", "cosh()")}}, {{jsxref("Math.sinh()", "sinh()")}}, {{jsxref("Math.tanh()", "tanh()")}}, {{jsxref("Math.acosh()", "acosh()")}}, {{jsxref("Math.asinh()", "asinh()")}}, {{jsxref("Math.atanh()", "atanh()")}}, {{jsxref("Math.hypot()", "hypot()")}}, {{jsxref("Math.trunc()", "trunc()")}}, {{jsxref("Math.sign()", "sign()")}}, {{jsxref("Math.imul()", "imul()")}}, {{jsxref("Math.fround()", "fround()")}}, {{jsxref("Math.cbrt()", "cbrt()")}} and {{jsxref("Math.clz32()", "clz32()")}} added.
{{SpecName('ESDraft', '#sec-math-object', 'Math')}}{{Spec2('ESDraft')}} 
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Browser compatibility

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{{Compat("javascript.builtins.Math")}}

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See also

+ + -- cgit v1.2.3-54-g00ecf