这个信号在 TypeScript 中是什么意思？

Question

In this code snippet

return new this(`${last}, ${first} ${middle}`.trim(),
            utils.age(birthday),
            gender
        );

what does this signal mean '?

Answer 1

If you mean the backtick symbol (`), it denotes a template literal or template string .

From the Typescript documentation :

Template literals can contain placeholders. These are indicated by the dollar sign and curly braces (${expression}). The expressions in the placeholders and the text between the backticks (` `) get passed to a function.

The default function just concatenates the parts into a single string. If there is an expression preceding the template literal (tag here), this is called a tagged template. In that case, the tag expression (usually a function) gets called with the template literal, which you can then manipulate before outputting.