如何使用 function 和两个参数 javaScript 进行字符串插值

Question

I am a complete newbie. But I am working on a piece of training code and hit a wall. I completed the project, however, I wanted to test an additional piece of code. I want to use string interpolation to show the user a message like this:

If this object were on ${planetName} it would weight ${thisMuch}.

But I am confused on how to call only one argument from a function with two parameters.

    function calculateWeight(earthWeight, planet) {
let weight;
if(planet === 'Mercury') {
weight = earthWeight * .378
return `${weight}`
}if(planet === 'Venus') {
weight = earthWeight * .907
return `${weight}`
}if(planet === 'Mars') {
weight = earthWeight * .377
return `${weight}`
}if(planet === 'Jupiter') {
weight = earthWeight * 2.36
return `${weight}`
}if(planet === 'Saturn') {
weight = earthWeight * 0.916
return `${weight}`
} else {
return 'Invalid Planet Entry. Try: Mercury, Venus, Mars, Jupiter, or Saturn.'
   }
}


// Uncomment the line below when you're ready to try out your function
 console.log(calculateWeight(100, 'Jupiter')) 

Answer 1

Couple of changes:

First there is a difference in the way you have written multiple if s and if , else-if . The first one will run all planet conditions even if the 1st one is satisfied. You do not want that.

Second, try to return your statement from inside the function. You are returning only weight for a planet.

With the statement in place all you need is the weight value and your job can be done with a single return statement.

 function calculateWeight(earthWeight, planet) { let weight; if(planet === 'Mercury') { weight = earthWeight *.378 }else if(planet === 'Venus') { weight = earthWeight *.907 }else if(planet === 'Mars') { weight = earthWeight *.377 }else if(planet === 'Jupiter') { weight = earthWeight * 2.36 }else if(planet === 'Saturn') { weight = earthWeight * 0.916 } else { return 'Invalid Planet Entry. Try: Mercury, Venus, Mars, Jupiter, or Saturn.' } return `If this object were on ${planet} it would weight ${weight}.` } // Uncomment the line below when you're ready to try out your function console.log(calculateWeight(100, 'Jupiter'))