將特定的預定義參數傳遞給函數

Question

讓它就這樣 ：

let something = (a , b ,  c = 0 ,  d = 0 ,  e = 0) =>
{console.log(`a is ${a}; b is ${b};c is ${c};d is ${d};e is ${e}`)};`

如果我給函數賦予兩個以上的參數，則分別將它們作為一個函數。 如果我想將值傳遞給“e”變量並跳過其他預定義的內容，該怎么辦？

Answer 1

只需傳遞undefined：

 let something = (a, b, c = 0, d = 0, e = 0) => { console.log(`a is ${a}; b is ${b}; c is ${c}; d is ${d}; e is ${e}`); }; something(1, 2, undefined, undefined, 3); 

您還可以將可選參數包裝在一個將被解構的參數中：

 let something = (a, b, {c=0, d=0, e=0} = {}) => { console.log(`a is ${a}; b is ${b}; c is ${c}; d is ${d}; e is ${e}`); }; something(1, 2); something(1, 2, {c: 3}); something(1, 2, {e: 3}); 

Answer 2

你可以將params作為一個對象。它有兩個好處，首先，你不必擔心順序，你不必將值傳遞給c或d。

let something = ({a , b ,  c = 0 ,  d = 0 ,  e = 0}) => {
  return `a is ${a}; b is ${b};c is ${c};d is ${d};e is ${e}`;
}
console.log(something({a: 12 , b: 13, e: 51})); //"a is 12; b is 13;c is 0;d is 0;e is 51"