JavaScript: Check if a number is a whole number or has a decimal place

JavaScript Math: Exercihse-38 with Solution

Check If Number Has Decimal

Write a JavaScript function to check if a number is a whole number or has a decimal place.

Note : Whole Numbers are simply the numbers 0, 1, 2, 3, 4, 5, ... (and so on). No Fractions!
Test Data :
console.log(number_test(25.66));
"Number has a decimal place."
console.log(number_test(10));
"It is a whole number."

Visual Presentation:

Sample Solution:

JavaScript Code:

// Define a function named number_test that checks if a number has a decimal place.
function number_test(n)
{
   // Calculate the difference between n and its floor value, and check if it is not equal to zero.
   var result = (n - Math.floor(n)) !== 0; 
   
   // If result is true, return 'Number has a decimal place.'; otherwise, return 'It is a whole number.'
   if (result)
      return 'Number has a decimal place.';
   else
      return 'It is a whole number.';
}

// Output the result of testing if 25.66 has a decimal place to the console.
console.log(number_test(25.66));

// Output the result of testing if 10 has a decimal place to the console.
console.log(number_test(10));

Output:

Number has a decimal place.
It is a whole number.

Flowchart:

Live Demo:

See the Pen javascript-math-exercise-38 by w3resource (@w3resource) on CodePen.

For more Practice: Solve these Related Problems:

• Write a JavaScript function that determines if a number is a whole number by checking for a fractional part using modulo.
• Write a JavaScript function that converts a number to a string and checks for the presence of a decimal point.
• Write a JavaScript function that compares Math.floor and Math.ceil of a number to decide if it has a decimal portion.
• Write a JavaScript function that uses bitwise operators to check if a number is integer-like or contains decimals.

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