JavaScript: Template String

New in JS2015.

String can also be created by bracketing text with ` (U+60: GRAVE ACCENT) This this called template string.

console.log(`my cat` === "my cat"); // true

Literal Line Break Allowed

Literal newline character is allowed:

// template string allow literal newline
let x = `aa
bb`;

console.log(x);
// prints in 2 lines

Embeded Expression

Any form ${expr} in tempate string will have the expr evaluated and result inserted into the string.

// template string example
console.log(
 `two plus three is ${2+3}`
); // two plus three is 5

The ${…} is called place-holder, or substitution string.

Here is a example with embedded variable:

// variable interpolation inside template string

let x = 76;

console.log(
 `You have ${x} points.`
); // You have 76 points.

When the expression is a object, its toString method is used to convert it to string. (or, with inheritance up to Object.toString()) [see Prototype and Inheritance]

Escape GRAVE ACCENT

If you want to include a GRAVE ACCENT in a template string, add a backslash in front, like this \`.

// escape grave mark in template string
console.log(
 `a\`b`
); // prints a`b

You can also escape ${…} by \${…} or $\{…}.

// escape the expression part in template string

let x = 2;

console.log(`${x}`); // prints 2

console.log(`\${x}`); // prints ${x}

console.log(`$\{x}`); // prints ${x}

• String Escape Sequence
• Unicode Escape Sequence

Nest Template String

Template string can be nested.

// nested template string

let x = "B";

console.log(
 `wow ${`A${x}C`}`
); // wow ABC

Tagged Template String

Tagged Template String