Question

When I’m writing Javascript code, I feel miss Ruby’s #{} method.So I implement it in JS.
But this code is not clean and beautiful. I want to make this method safe, But I can’t do it.
Do you have any idea that this code makes safe or beautiful? Thanks in advance.

String.prototype.to_s = function(){
    var str = this.toString();


    // convert function is bad  because it use eval...
    var convert = function(s){
        return eval(s);
    };

    // It's slower because call ReGexp method too many times.
    while(/#{(\w+)}/.test(str)){


        var matchStr =RegExp.$1;

        var str = str.replace(/#{(\w+)}/,convert(matchStr));

    }
    return str;
};



var name = "nobi";

var age = 23;

var body = "I'm #{name} and I am #{age} years old".to_s();
// I'm nobi and I am 23 years old.


console.log(body);

Answer 1

That sort of hack can’t be made “beautiful” – it doesn’t even work for non-globals. Given ES6 support, though, you don’t need the hack; string interpolation is now a part of the language.

var body = `I'm ${name} and I am ${age} years old`;

Failing that, string concatenation is often readable enough with ES5 and earlier:

var body = "I'm " + name + " and I am " + age + " years old";

CoffeeScript, a language that compiles to JavaScript, also supports this feature.