array_duplicate.js

//using Set ES6
console.log('--------using Set ES6--------');

const fruits=['mango','banana','orange','mango','orange','orange','banana'];
console.log('fruits-->',fruits);
const fruitsUniqueSet=new Set(fruits);
console.log('fruitsUniqueSet-->',fruitsUniqueSet);
const backFruitsArray=[...fruitsUniqueSet];
console.log('backFruitsArray-->',backFruitsArray);

Array.from(new Set(fruits));
console.log(Array.from(new Set(fruits)));

//Using filter
console.log('-------Using filter---------');

const fruits2=['mango','banana','orange','mango','orange','orange','banana'];
console.log(fruits2.indexOf('mango'));
console.log(fruits2.indexOf('orange'));
console.log(fruits2.indexOf('banana'));
console.log('----------------');

const fruits2Unique=fruits2.filter((item,index)=>{
    console.log(item,index,fruits2.indexOf(item),fruits2.indexOf(item)===index);
    return fruits2.indexOf(item)===index;
});
console.log(fruits2Unique);
console.log('----------------');
const fruits3Unique=fruits2.filter((item,index)=>{
    console.log(item,index,fruits2.indexOf(item),fruits2.indexOf(item)===index);
    return fruits2.indexOf(item)!=index;
});
console.log(fruits3Unique);
console.log('----------------');

//Using reduce
console.log('--------Using reduce--------');

const fruits4=['mango','banana','orange','mango','orange','orange','banana','strawberry'];
console.log(fruits4.includes('orange'));

fruits4.reduce((fruits4Unique,item)=>{
    console.log(item,fruits4Unique,fruits4Unique.includes(item),fruits4Unique.includes(item)?fruits4Unique:[...fruits4Unique,item]);
    return fruits4Unique.includes(item)?fruits4Unique:[...fruits4Unique,item];
},[]);