JavaScript Math.exp() is a built-in method that returns the value of ex, where e is Euler’s number (approximately 2.7183), and x is the number passed to it. It is a static method of Math, so you always use it as Math.exp(), not as a method of a Math object.
JavaScript exponential
To find an exponential value in JavaScript, you can use the Math.exp() method. The Math.exp() function returns ex, where x is an argument, and e is the Euler’s number, a base of the natural logarithms.
Syntax
Math.exp(x)
Parameter(s)
The variable x, whose exponential value is ex, must be determined.
Return Value
The exponential value ex.
Visual representation
Note
- For a positive argument x, Math.log(Math.exp(x)) gives the value x.
- If the argument is negative infinity, then this method returns 0.
- If the argument is positive infinity, then this method returns positive infinity.
- If an argument is positive zero or negative zero, then this method returns 1.
- If the passed value is not a valid number, the method returns NaN.
- If the passed value is null, the method returns 1.
Example 1
var a = 1;
var b = -1;
var c = 2;
var d = 3;
console.log(Math.exp(a));
console.log(Math.exp(b));
console.log(Math.exp(c));
console.log(Math.exp(d));
Output
2.718281828459045
0.36787944117144233
7.38905609893065
20.085536923187668
Example 2
var a = "JavaScript";
var b;
console.log(Math.exp(a));
console.log(Math.exp(b));
Output
NaN
NaN
Example 3
JavaScript exp() method cannot be used with complex arguments, as only integer arguments are accepted.
console.log(Math.exp(2+i));
Output
ReferenceError: i is not defined
Example 4
The following example demonstrates that for a positive x: ln(ex) = x.
var x = 10;
var a = Math.exp(x);
console.log(Math.log(a));
Output
10
Example 5
The following example demonstrates the case of the parameter as infinity(positive/negative) and zero(positive/negative).
var a = Number.POSITIVE_INFINITY;
var b = Number.NEGATIVE_INFINITY;
var c = 0;
var d = -0;
console.log(Math.exp(a));
console.log(Math.exp(b));
console.log(Math.exp(c));
console.log(Math.exp(d));
Output
Infinity
0
1
1
Example 6
The following example demonstrates that if null is passed as an ent, this method returns 1.
var a = null;
var b = "";
var c = [];
console.log(Math.exp(a));
console.log(Math.exp(b));
console.log(Math.exp(c));
Output
1
1
1
Example 7
The following example demonstrates the application of this method in a simple programming context.
Given any x, compute the value of the infinite series:
1 + x/1! + x2/2! + x3/3! + x4/4! + …
[Now, it would be tough to devise a program to solve this. But since
1 + x/1! + x2/2! + x3/3! + x4/4! + … = ex,
It can be done within a few lines of code].
var x;
const r = require('readline');
const rl = r.createInterface({
input: process.stdin,
output: process.stdout
});
const prompt1 = () => {
return new Promise((resolve, reject) => {
rl.question('x: ', (answer) => {
x = answer;
resolve();
});
});
};
const main = async () => {
await prompt1();
rl.close();
console.log();
console.log('The value of the series 1 + x/1! + (x^2)/2! + (x^3)/3! + ... :');
console.log(Math.exp(x));
}
main();
Output
Test Case 1:
x: 1
The value of the series 1 + x/1! + (x^2)/2! + (x^3)/3! + ... :
2.718281828459045
Test Case 2:
x: 2
The value of the series 1 + x/1! + (x^2)/2! + (x^3)/3! + ... :
7.38905609893065
That’s it.
Compatibility(Version and above)
- Google Chrome v1
- Internet Explorer v3
- Firefox v1
- Edge v12
- Opera
- Safari v1
- Android webview v1
- Chrome for Android v18
- Firefox for Android v4
- Opera for Android
- Safari on iOS v1
- Samsung Internet v1.0
- Node.js
JavaScript version: ECMAScript 1
That’s it.