JavaScript Math log1p() Method

Javascript Math.log1p() is an inbuilt function in JavaScript that gives the value of the natural logarithm of 1 + p number. The natural logarithm is of base e, where e is an irrational and transcendental number approximately equal to 2.718.

Syntax:

Math.log1p(1 + p)

Below example illustrate the JavaScript Math.log1p() Method in JavaScript:

Example 1: In this example, we will find the logarithms of some basic numbers.

javascript

// Different numbers are being taken
// as the parameter of the function.
console.log(Math.log1p(1000));
console.log(Math.log1p(12));
console.log(Math.log1p(26));
console.log(Math.log1p(5));

Output:

6.90875477931522
2.5649493574615367
3.295836866004329
1.791759469228055

Example 2: In this example, we will use a for loop to get the logarithms of numbers from 1 to 19 with an increment of 3.

javascript

// Taken parameter from 1 to 19 incremented by 3.
for (i = 1; i < 20; i += 3) {
    console.log(Math.log1p(i));
}

Output:

0.6931471805599453
1.6094379124341003
2.0794415416798357
2.3978952727983707
2.639057329615259
2.833213344056216
2.995732273553991

Errors and exceptions: Parameters for this function should always be a number otherwise it returns NaN i.e, not a number when its parameter is taken as a string.

Example 1: Here NaN comes in output as we have passed a string in the Math.log1p() function.

javascript

// Parameters for this function should always be a
// number otherwise it return NaN i.e, not a number
// when its parameter taken as string.
console.log(Math.log1p("gfg"));

Output:

NaN

Example 2: This function gives an error when its parameter is taken as a complex number because it accepts only integer value as the parameter.

javascript

// Parameters can never be a complex number because
// it accept only integer value as the parameter.
console.log(Math.log1p(1 + 2i));

Output:

Error: Invalid or unexpected token

Example 3: This function returns NaN i.e, not a number if the parameter is less than -1 because the number should be any positive number i.e, greater than 0.

javascript

// This function return NaN i.e, not a number
// if the parameter is less
// than -1 because number should be
// any positive number i.e, greater than 0.
console.log(Math.log1p(-2));

Output: