2

Typescript/JavaScript question.

I created my own log() method where I could switch logging on demand (not important), but right now I use a simple console.log(). Here is the code:

log(message: any): void {
    console.log(message)
}

Recently I decided to pass multiple parameters, since console.log supports any number of parameters using like: console.log(a, b, c). So, I decided to use rest parameter and adjust my method to the following:

log(...message: any[]): void {
    console.log(message)
}

Works great. However, when I use my log method with any number parameters, the console.log outputs an array and not separate values as if I called it directly. I can understand why, because the message could be seen as a single parameter of array type. But how would I pass array to console.log (or any other alike function) and tell that it is not a single parameter of array type, but multiple parameters?

I would really like to avoid defining 10 optional parameters passing them as is :)

tgralex
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  • Possible duplicate of [Spread Syntax ES6](https://stackoverflow.com/questions/34559918/spread-syntax-es6) – VLAZ Oct 04 '19 at 19:56
  • Also touches on spread syntax: [Spread Syntax vs Rest Parameter in ES2015 / ES6](https://stackoverflow.com/questions/33898512/spread-syntax-vs-rest-parameter-in-es2015-es6) – VLAZ Oct 04 '19 at 19:57

1 Answers1

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There are at least 2 options for doing this:

Option 1: 

log(...message: any[]): void {
    console.log(...message)
}

Option 2: Use Function.prototype.apply.

E.g.

log(...message: any[]): void {
    console.log.apply(null, message)
}

This will apply your array of arguments as you expect.

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function/apply

nicholascm
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  • Thank you very much!, the first solution worked as expected, and there was no need to try second one :) – tgralex Oct 04 '19 at 20:28