Javascript 过滤器 function，行为不符合预期

Question

My code is very simple: I'm using the filter to modify one element of the array. I checked that the if state does hit and "sattar" is returned. However, both arrays: person and new_p print: orignal [ 'ali', 'hassan', 'ameer' ] changed [ 'ali', 'hassan', 'ameer' ]

What am I missing here?

 const person = ["ali", "hassan", "ameer"]; const new_p = person.filter(p => { if (p === "hassan") { return "sattar" } return p }) console.log("orignal", person); console.log("changed", new_p);

Answer 1

Use .map instead:

 const person = ["ali", "hassan", "ameer"]; const new_p = person.map(p => { if (p === "hassan") { return "sattar" } return p }) console.log("orignal", person); console.log("changed", new_p);

A shorter version:

 const person = ["ali", "hassan", "ameer"]; const new_p = person.map(p => p === "hassan"? "sattar": p); console.log("orignal", person); console.log("changed", new_p);

Answer 2

use .map instead .filter

const person = ["ali", "hassan", "ameer"];
const new_p = person.map((p) => {
   if (p == "hassan") {
      return "sattar";
   }
   return p;
})

console.log("orignal", person);
console.log("changed", new_p);