node.js中的反引号

Question

I am attempting to use the following code as a file test2.js with node.js version 12.0.

let apiKey = '117fa18eaf7312fa52f593c6d52fc48d';
let id = '6094817';
let xu1 = `http://api.openweathermap.org/data/2.5.weather?id=$(id)&APPID=$(apiKey)`;
console.log('xul is: ', xul);

I get the following results and I am unable to understand why.

jgossage@jgossage-XPS-8700:/LinuxData/Projects/node-weather$ node test2.js
/LinuxData/Projects/node-weather/test2.js:4
console.log('value is: ', xul);
                          ^

ReferenceError: xul is not defined
    at Object.<anonymous> (/LinuxData/Projects/node-weather/test2.js:4:27)
    at Module._compile (internal/modules/cjs/loader.js:936:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:947:10)
    at Module.load (internal/modules/cjs/loader.js:790:32)
    at Function.Module._load (internal/modules/cjs/loader.js:703:12)
    at Function.Module.runMain (internal/modules/cjs/loader.js:999:10)
    at internal/main/run_main_module.js:17:11

The only thing I can see is that possibly the template string is not being handled properly, resulting in the variable xul being not defined.

Answer 1

As @Andreas mentioned you have a typo it should be console.log('value is: ', xu1);

but also even if you run that you get xu1 is: http://api.openweathermap.org/data/2.5.weather?id=$(id)&APPID=$(apiKey)

That is because you have to use ${} instead of $(). So the final fix is

let xu1 = `http://api.openweathermap.org/data/2.5.weather?id=${id}&APPID=${apiKey}`;