JavaScript: Check whether a variable is numeric or not

JavaScript Math: Exercise-16 with Solution

Check If Value is Numeric

Write a JavaScript function to check whether a variable is numerical or not.

Test Data:
console.log(is_Numeric(12));
console.log(is_Numeric('abcd'));
console.log(is_Numeric('12'));
console.log(is_Numeric(' '));
console.log(is_Numeric(1.20));
console.log(is_Numeric(-200));
Output:
true
false
true
false
true
true

Visual Presentation:

Sample Solution:

JavaScript Code:

// Define a function named is_Numeric that checks if a value is numeric.
function is_Numeric(num) {
    // Check if the value can be parsed as a floating-point number and is finite.
    return !isNaN(parseFloat(num)) && isFinite(num);
}

// Output the result of checking if 12 is numeric to the console.
console.log(is_Numeric(12));
// Output the result of checking if 'abcd' is numeric to the console.
console.log(is_Numeric('abcd'));
// Output the result of checking if '12' is numeric to the console.
console.log(is_Numeric('12'));
// Output the result of checking if ' ' (empty string) is numeric to the console.
console.log(is_Numeric(' '));
// Output the result of checking if 1.20 is numeric to the console.
console.log(is_Numeric(1.20));
// Output the result of checking if -200 is numeric to the console.
console.log(is_Numeric(-200));

Output:

true
false
true
false
true
true

Flowchart:

Live Demo:

See the Pen javascript-math-exercise-16 by w3resource (@w3resource) on CodePen.

For more Practice: Solve these Related Problems:

• Write a JavaScript function that checks whether a variable is numeric using parseFloat and isNaN.
• Write a JavaScript function that validates if an input is a number by handling empty strings and whitespace.
• Write a JavaScript function that uses regular expressions to test if a variable represents a numeric value.
• Write a JavaScript function that employs isFinite to determine if a value is numeric and returns true or false.

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