destructing.js

// destruct array elements in variables
let arr = [1,2,3,4,5]
let [a,b] = arr
console.log(`a is ${a} and b is ${b}`)


//destruct array elements with skipping
let [a1, ,c]=arr
console.log(`a is ${a1} and b is ${c}`)


//destruct array to variables and array
let [elm1,elm2,...rest]=arr
console.log(`elm1 is ${elm1}, elm2 is ${elm2} and rest ${rest}`)


//destruct object to variables and array of properties
let {a:prop,b:prop2,...restPropObject}={a:1,b:2,c:3}
console.log(`prop is ${prop}, prop2 is ${prop2} and rest.c ${restPropObject.c}`)


//destruct with default value
let [elm11=1,elm21=2,...rest1] = [1,undefined,6]
console.log(`elm1 is ${elm11}, elm2 is ${elm21} and rest ${rest1}`)


// swaping fueture in arries
let val1=1,val2=3;
[val2,val1]=[val1,val2]
console.log(`val1 is ${val1}, val2 is ${val2}`)


// destruct with objects
let {a:a11,b:b1}= {a:1,b:2}
console.log(` a is ${a11}, b is ${b1}`)


// list of objects destruction
let people =[
  { name :"abdalla",
    friends:[{
      fname:"ahmed",
      age:23
    },{
      fname:"khaled",
      age:25
    }  ]
  },{ name :"ali",
    friends:[{
      fname:"mohammed",
      age:32
    },{
      fname:"saeed",
      age:25
    }  ]
  }
]
for(let{name,friends} of people){
  for(let{fname} of friends){
    console.log(fname)
  }
  console.log(name)
}


// claculated key in object destruction
let key = "c"
let {[key]:a22}={a:1,b:2,c:3}
console.log(a22)