You can take advantage of Template Literals and use this syntax:
`String text ${expression}`
Template literals are enclosed by the back-tick (` `) (grave accent) instead of double or single quotes.
This feature has been introduced in ES2015 (ES6).
Example
var a = 5;
var b = 10;
console.log(`Fifteen is ${a + b}.`);
// "Fifteen is 15.
How neat is that?
Bonus:
It also allows for multi-line strings in javascript without escaping, which is great for templates:
return `
<div class="${foo}">
...
</div>
`;
Browser support:
As this syntax is not supported by older browsers (mostly Internet Explorer), you may want to use Babel/Webpack to transpile your code into ES5 to ensure it will run everywhere.
Side note:
Starting from IE8+ you can use basic string formatting inside console.log:
console.log('%s is %d.', 'Fifteen', 15);
// Fifteen is 15.
You can take advantage of Template Literals and use this syntax:
`String text ${expression}`
Template literals are enclosed by the back-tick (` `) (grave accent) instead of double or single quotes.
This feature has been introduced in ES2015 (ES6).
Example
var a = 5;
var b = 10;
console.log(`Fifteen is ${a + b}.`);
// "Fifteen is 15.
How neat is that?
Bonus:
It also allows for multi-line strings in javascript without escaping, which is great for templates:
return `
<div class="${foo}">
...
</div>
`;
Browser support:
As this syntax is not supported by older browsers (mostly Internet Explorer), you may want to use Babel/Webpack to transpile your code into ES5 to ensure it will run everywhere.
Side note:
Starting from IE8+ you can use basic string formatting inside console.log:
console.log('%s is %d.', 'Fifteen', 15);
// Fifteen is 15.
Prior to Firefox 34 / Chrome 41 / Safari 9 / Microsoft Edge, nope, that was not possible in javascript. You would have to resort to:
var hello = "foo";
var my_string = "I pity the " + hello;
Videos
Introduced in ES6 as "template strings"
MDN docs: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Template_literals
const name = "Nick"
const greeting = `Hello ${name}` // "Hello Nick"
https://www.npmjs.com/package/stringinject
https://github.com/tjcafferkey/stringinject
I created this function to do exactly this, it will allow you to pass in a string, and an object with keys that will replace placeholder values in the string with their values like below:
var str = stringInject("My username is {username} on {platform}", { username: "tjcafferkey", platform: "GitHub" });
// My username is tjcafferkey on Github
With Node.js v4 , you can use ES6's Template strings
var my_name = 'John';
var s = `hello ${my_name}, how are you doing`;
console.log(s); // prints hello John, how are you doing
You need to wrap string within ` (backtick) instead of ' (apostrophe)
Note, from 2015 onwards, just use backticks for templating
let a = `hello ${name}` // NOTE!!!!!!!! ` not ' or "
Note that it is a backtick, not a quote.
If you want to have something similar, you could create a function:
function parse(str) {
var args = [].slice.call(arguments, 1),
i = 0;
return str.replace(/%s/g, () => args[i++]);
}
Usage:
s = parse('hello %s, how are you doing', my_name);
This is only a simple example and does not take into account different kinds of data types (like %i, etc) or escaping of %s. But I hope it gives you some idea. I'm pretty sure there are also libraries out there which provide a function like this.