backticks.md

Backticks allow to specify a "template function" before the first backtick.

The syntax is:

let str = func`my string`;

The function func is automatically called and receives the array of string pieces split by ${...} embeds and the list of embedded ${...} values.

It's better to see the example:

function love(s, v1, v2) {
  alert( s[0] ); // Hello:
  alert( s[1] ); //  and 
  alert( s[2] ); // !

  alert( v1 ); // Ilya
  alert( v2 ); // Julia

  alert( s.raw[0] ); // Hello:\n

  return v1 + ' ♥ ' + v2;
}

let mom = "Julia";
let dad = "Ilya";

//              s[0]    | v1 |  s[1] | v2 | s[2]
let str = love`Hello:\n ${mom}  and  ${dad}!`;

alert(str); // 'Julia ♥ Ilya'

The string inside love`string` is split into pieces by embeds. The result is passed to love:

• The first parameter s stores the pieces, here s = ["Hello:\n ", " and ", "!"].
• The special proeprty s.raw contains unparsed values, the special characters are not processes.
• Then follow the values of embeds: v1 = mom, v2 = data.

Templating functions allow to

• The first parameter strings is a

In the example above, love is the name for the function. It is called with an array