7.8. Template Literals

Earlier, we used concatenation to combine strings and variables together in order to create specific output:

Example

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let name = Jack;
let currentAge = 9;

console.log("Next year, " + name + " will be " + (currentAge + 1) + ".");

Console Output

Next year, Jack will be 10.

Unfortunately, this process quickly gets tedious for any output that depends on multiple variables. Often, concatenation requires multiple test runs of the code in order to check for syntax errors and proper spacing within the output. Fortunately, JavaScript offers us a better way to accomplish this process.

Template literals allow for the automatic insertion of expressions (including variables) into strings.

While normal strings are enclosed in single or double quotes (' or "), template literals are enclosed in back-tick characters, `. Within a template literal, any expression surrounded by ${ } will be evaluated, with the resulting value included in the string.

Example

Template literals allow for variables and other expressions to be directly included in strings.

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let name = "Jack";
let currentAge = 9;

console.log(`Next year, ${name} will be ${currentAge + 1}.`);

Console Output

Next year, Jack will be 10.

Besides allowing us to include data in strings in a cleaner, more readable way, template literals also allow us to easily create multi-line strings without using string concatenation or special characters.

Example

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let poem = `The mind chases happiness.
The heart creates happiness.
The soul is happiness
And it spreads happiness
All-where.

– Sri Chinmoy`;

console.log(poem);

Console Output

The mind chases happiness.
The heart creates happiness.
The soul is happiness
And it spreads happiness
All-where.

– Sri Chinmoy

Note

The ECMAScript specifications define the standard for JavaScript. The 6th edition, known as ES2015, added template literals. Not only are template literals relatively new to JavaScript, but you may encounter environments---such as older web browsers---where they are not supported.

7.8.1. Check Your Understanding

Question

Mad Libs are games where one player asks the group to supply random words (e.g. "Give me a verb," or, "I need a color"). The words are substituted into blanks within a story, which is then read for everyone's amusement. In elementary school classrooms, giggles and hilarity often ensue. TRY IT!

Refactor the following code to replace the awkward string concatenation with template literals. Be sure to add your own choices for the variables.

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let pluralNoun = ;
let name = ;
let verb = ;
let adjective = ;
let color = ;

console.log("JavaScript provides a "+ color +" collection of tools — including " + adjective + " syntax and " + pluralNoun + " — that allows "+ name +" to "+ verb +" with strings.")