script.js - 삼항연산자

let person ={name:"kim",age:23}

if(person){
  console.log(person.name)
}else {
  console.log("there is no person")
}

<출력결과>

kim

 

let person = null //false

if(person){
  console.log(person.name)
}else {
  console.log("there is no person")
}

<출력결과>

there is no person

 

* null은 false 따라서 if문은 거짓!

 

----

 

let person ={name:"kim",age:23}

if(person){
  console.log(person.name)
}else {
  console.log("there is no person")
}

console.log(person?person.name:"there is no person")

<출력결과>

kim
kim

 

let person =null
if(person){
  console.log(person.name)
}else {
  console.log("there is no person")
}

console.log(person?person.name:"there is no person")

<출력결과>

there is no person
there is no person