Use of String.Format in JavaScript?

Question

This is driving me nuts. I believe I asked this exact same question, but I can\'t find it any more (I used Stack Overflow search, Google Search, manually searched my po

Answer 1

Here is a useful string formatting function using regular expressions and captures:

function format (fmtstr) {
  var args = Array.prototype.slice.call(arguments, 1);
  return fmtstr.replace(/\{(\d+)\}/g, function (match, index) {
    return args[index];
  });
}

Strings can be formatted like C# String.Format:

var str = format('{0}, {1}!', 'Hello', 'world');
console.log(str); // prints "Hello, world!"

the format will place the correct variable in the correct spot, even if they appear out of order:

var str = format('{1}, {0}!', 'Hello', 'world');
console.log(str); // prints "world, Hello!"

Hope this helps!