JavaScript: Create a Zerofilled value with optional +, - sign

JavaScript String: Exercise-36 with Solution

Write a JavaScript function to create a zero-filled value with an optional +, - sign.

Test Data:
console.log(zeroFill(120, 5, '-'));
console.log(zeroFill(29, 4));

Sample Solution:

JavaScript Code:

// Define a function named zeroFill with three parameters: number, width, and osign
function zeroFill(number, width, osign) {
    // Convert the absolute value of the number to a string and store it in the variable num
    var num = '' + Math.abs(number),
        // Calculate the number of zeros to be added to the left based on the specified width
        zerosw = width - num.length,
        // Determine if the number is positive
        sign = number >= 0;
    // Construct and return the zero-filled string
    return (sign ? (osign ? '+' : '') : '-') +
        // Append zeros to the left of the number using exponential notation and substring
        Math.pow(10, Math.max(0, zerosw)).toString().substr(1) + num;

// Test the zeroFill function with different arguments and output the result
console.log(zeroFill(120, 5, '-')); // Output: "--120"
console.log(zeroFill(29, 4)); // Output: "0029"




In the exercise above,

  • The "zeroFill()" function takes three parameters: 'number', 'width', and 'osign'.
  • It converts the absolute value of the input number to a string and stores it in the variable 'num'.
  • It calculates the number of zeros ('zerosw') needed to pad the number to the specified width.
  • It determines whether the number is positive and stores this information in the 'sign' variable.
  • The function constructs the zero-filled string by adding a sign (if specified), padding zeros based on the calculated width, and appending the original number.
  • The function returns the constructed zero-filled string.
  • Two test cases are provided to demonstrate the "zeroFill()" function with different arguments, and their results are printed using console.log.


Flowchart: JavaScript- Create a Zerofilled value with optional +, - sign

Live Demo:

See the Pen JavaScript Create a Zerofilled value with optional +, - sign-string-ex-36 by w3resource (@w3resource) on CodePen.

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