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JavaScript: Pad (left, right) a string to get to a determined length

JavaScript String: Exercise-20 with Solution

Write a JavaScript function that can pad (left, right) a string to get to a determined length.

Test Data:
console.log(formatted_string('0000',123,'l'));
console.log(formatted_string('00000000',123,''));
Output:
"0123"
"12300000"

Pictorial Presentation:

JavaScript: Pad (left, right) a string to get to a determined

Sample Solution:-

HTML Code:

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>Write a JavaScript function that can pad (left, right) a string to get to a determined length.</title>
</head>
<body>

</body>
</html>

JavaScript Code:

function formatted_string(pad, user_str, pad_pos)
{
  if (typeof user_str === 'undefined') 
    return pad;
  if (pad_pos == 'l')
     {
     return (pad + user_str).slice(-pad.length);
     }
  else 
    {
    return (user_str + pad).substring(0, pad.length);
    }
}
console.log(formatted_string('0000',123,'l'));
console.log(formatted_string('00000000',123,''));

Sample Output:

0123
12300000

Flowchart:

Flowchart: JavaScript- Pad (left, right) a string to get to a determined length

Live Demo:

See the Pen JavaScript Pad (left, right) a string to get to a determined length - string-ex-20 by w3resource (@w3resource) on CodePen.


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JavaScript: Tips of the Day

Tagged template literals

function getPersonInfo(one, two, three) {
  console.log(one);
  console.log(two);
  console.log(three);
}

const person = 'Lydia';
const age = 21;

getPersonInfo`${person} is ${age} years old`;

If you use tagged template literals, the value of the first argument is always an array of the string values. The remaining arguments get the values of the passed expressions!

Ref: https://bit.ly/323Y0P6