How to trim a string to N chars in Javascript?

Question

How can I, using Javascript, make a function that will trim string passed as argument, to a specified length, also passed as argument. For example:

var strin         


        

Answer 1

Little late... I had to respond. This is the simplest way.

// JavaScript
function fixedSize_JS(value, size) {
  return value.padEnd(size).substring(0, size);
}

// JavaScript (Alt)
var fixedSize_JSAlt = function(value, size) {
  return value.padEnd(size).substring(0, size);
}

// Prototype (preferred)
String.prototype.fixedSize = function(size) {
  return this.padEnd(size).substring(0, size);
}

// Overloaded Prototype
function fixedSize(value, size) {
  return value.fixedSize(size);
}

// usage
console.log('Old school JS -> "' + fixedSize_JS('test (30 characters)', 30) + '"');
console.log('Semi-Old school JS -> "' + fixedSize_JSAlt('test (10 characters)', 10) + '"');
console.log('Prototypes (Preferred) -> "' + 'test (25 characters)'.fixedSize(25) + '"');
console.log('Overloaded Prototype (Legacy support) -> "' + fixedSize('test (15 characters)', 15) + '"');

Step by step. .padEnd - Guarentees the length of the string

"The padEnd() method pads the current string with a given string (repeated, if needed) so that the resulting string reaches a given length. The padding is applied from the end (right) of the current string. The source for this interactive example is stored in a GitHub repository." source: developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/…

.substring - limits to the length you need

If you choose to add ellipses, append them to the output.

I gave 4 examples of common JavaScript usages. I highly recommend using the String prototype with Overloading for legacy support. It makes it much easier to implement and change later.