I want to write backtick inside backtick. [es6]
How do you create backtick in backtick ?
const apple = 'apple';
const grape = 'grape';
const money1 = 2000;
const money2 = 1000;
// before
console.log[`${apple} = ${grape === 'grape' ? '[' + money1 + ']' : '[' + money2 + ']'`;
// after
String.raw[{ raw: strings }, ...values];
console.log[identity`Hi\n${2 + 3}!`];
// Hi
// 5!
This is useful for many tools which give special treatment to literals tagged by a particular name.
const html = [strings, ...values] => String.raw[{ raw: strings }, ...values];
// Some formatters will format this literal's content as HTML
const doc = html`
Hello
Hello world!
`;
Tagged templates and escape sequences
In normal template literals, the escape sequences in string literals are all allowed. Any other non-well-formed escape sequence is a syntax error. This includes:
\followed by any decimal digit other than0, or\0followed by a decimal digit; for example\9and\07[which is a deprecated syntax]\xfollowed by fewer than two hex digits [including none]; for example\xz\unot followed by{and followed by fewer than four hex digits [including none]; for example\uz\u{}enclosing an invalid Unicode code point — it contains a non-hex digit, or its value is greater than10FFFF; for example\u{110000}and\u{z}
Note: \ followed by other characters, while they may be useless since nothing is escaped, are not syntax errors.
However, this is problematic for tagged templates, which, in addition to the "cooked" literal, also have access to the raw literals [escape sequences are preserved as-is].
Tagged templates should allow the embedding of languages [for example DSLs, or LaTeX], where other escapes sequences are common. Therefore, the syntax restriction of well-formed escape sequences is removed from tagged templates.
latex`\unicode`;
// Throws in older ECMAScript versions [ES2016 and earlier]
// SyntaxError: malformed Unicode character escape sequence
However, illegal escape sequences must still be represented in the "cooked" representation. They will show up as undefined element in the "cooked" array:
function latex[str] {
return { cooked: str[0], raw: str.raw[0] };
}
latex`\unicode`;
// { cooked: undefined, raw: "\\unicode" }
Note that the escape-sequence restriction is only dropped from tagged templates, but not from untagged template literals:
const bad = `bad escape sequence: \unicode`;
Specifications
| ECMAScript Language Specification # sec-template-literals |
Browser compatibility
BCD tables only load in the browser