有人可以解释一下这段代码的第二部分吗？

Question

let a = [101, 103, 222, 97, 105];

var i = 0;
a.forEach(function(v){
  v == 97 || v == 101 || v == 105 || v==111 || v ==117 ? a[i++] = String .fromCharCode(v) : a[i++] = v;}),a;


console.log(a);

result: [ 'e', 103, 222, 'a', 'i' ]

I do understand we are looping through the array and looking for any matching values and i know what the rest of the code does, but I don't understand the part after the ? .

Answer 1

The ternary operator is just a weird (or minified) way of saying:

if (v == 97 || v == 101 || v == 105 || v==111 || v ==117) {
    a[i] = String.fromCharCode(v); // The character represented by the number v. e.g 97 => 'a'
} else {
    a[i] = v; // The number v without any conversion
}
i++;

Answer 2

Your code is checking for vowels code in an array, if it matches it replaces with the text representation else the number.

Simplified version of your code (if you understand this )-

 let a = [101, 103, 222, 97, 105]; a.forEach(function(v, i){ this[i] = (v == 97 || v == 101 || v == 105 || v==111 || v ==117)? String.fromCharCode(v): v; }, a); console.log(a);

Your code is having - a[i++] = v;}),a; I think ,a is referring to the second argument of foreach() loop.

Answer 3

I'd write it like this. Basically some numbers get replaced with chars.

 let a = [101, 103, 222, 97, 105]; for (i = 0; i < a.length; i++) { if ([97, 101, 105, 111, 117].includes(a[i])) { // Replace int with char a[i] = String.fromCharCode(a[i]) } } console.log(a);