JavaScript 中的 ${value} 不起作用

Question

I do have a very simple use case:

it('Formatting with ${}', () => {
   const value = 1
   const info = 'the result is: ${value}'

   assert.equal(info, 'the result is: 1')
})

But it doesn't work and I can't see why. It's using ES6 because arrow function works. I tried let instead of const, even var. Nothing works.

Can anybody help?

Best regards, Torsten

Answer 1

You have to use back-ticks ( ` ) instead of single quote ( ' ) or double quote ( " ) to use string interpolation

it('Formatting with ${}', () => {
    const value = 1
    const info = `the result is: ${value}`

    assert.equal(info, 'the result is: 1')
})

Answer 2

Do

`the result is: ${value}`

instead of 'the result is: ${value}' .

This happens because in JavaScript there's a concept of Template literals which let's user evaluate embedded expressions . You can read more about it in the link provided.

Answer 3

Instead of 'result is: ${value}'

Please use Backticks

 const test = 'hello!' // Template Literal console.log(`testing: ${test}`)

If you dont know where Is the Backtick is Mostly near the Esc button

Hopes this help