Filter duplicate records and push into array with additional condition using js-CodePudding

I wan to filter the list of objects where city and state are not same, and then create a list of cities out of the filtered objects where temperature is less than 40. but condition is both sate and city should not be same

let arr = [
{
city:"chennai",
state: "tamilnadu",
temp: 44
},
 {
city:"coimbator",
state: "tamilnadu",
temp: 39
},
{
city:"mumbai",
state: "maharashtra",
temp: 32
},
{
city:"delhi",
state: "delhi",
temp: 24
},
{
city:"kolkata",
state: "west bengal",
temp: 28
}
];

Javascript code:

const uniqueStateCity = [];

const unique = arr.filter(element => {
const isDuplicate = uniqueStateCity.includes(element.city);
  
 if (!isDuplicate) {
  
  if(element.temp < 40)
  {
    uniqueStateCity.push(element.city );
    return true;
  
  }
}
  return false;
   
});

console.log(unique );

CodePudding user response：

You should try this in your code!

just put condition in the result statement with arrow function and you are good to go.

    let arr = [
  {
    city: "chennai",
    state: "tamilnadu",
    temp: 44,
  },
  {
    city: "coimbator",
    state: "tamilnadu",
    temp: 39,
  },
  {
    city: "mumbai",
    state: "maharashtra",
    temp: 32,
  },
  {
    city: "delhi",
    state: "delhi",
    temp: 24,
  },
  {
    city: "kolkata",
    state: "west bengal",
    temp: 28,
  },
];

const result = arr.filter((data) => data.temp < 40 && data.state !== data.city);
const data = result.map((x) => x.city);
console.log(data);

CodePudding user response：

let arr = [
  {
    city: "chennai",
    state: "tamilnadu",
    temp: 44,
  },
  {
    city: "coimbator",
    state: "tamilnadu",
    temp: 39,
  },
  {
    city: "mumbai",
    state: "maharashtra",
    temp: 32,
  },
  {
    city: "mumbai",
    state: "maharashtra",
    temp: 32,
  },
  {
    city: "delhi",
    state: "delhi",
    temp: 24,
  },
  {
    city: "kolkata",
    state: "west bengal",
    temp: 28,
  },
];
const result = [
...new Set(
arr.filter((data) => data.temp < 40 && data.state !== data.city).map((data) => data.city)
)
];
console.log(result);

CodePudding user response：

Since you want to filter out the objects having same names for city and state and with temperature greater than 40.

Also if your original arr has duplicate objects, and you want an array of unique objects. You can use:

const result = arr.filter(data => data.temp < 40 && data.state !== data.city);

for (let i = 0; i < result.length;   i) {
    for (let j = 0; j < result.length;   j) {
        if ( i !== j && 
             result[i].city === result[j].city && 
             result[i].state === result[j].state && 
             result[i].temp === result[j].temp
        ) {
            result.splice(j, 1);
        }
    }
}

CodePudding user response：

This checks for uniqueness of city and state values and also handles your additional conditions. It will not add values which have the same city and the same state value as any other object in the array.

const arr = [
  {
    city: "chennai",
    state: "tamilnadu",
    temp: 44,
  },
  {
    city: "coimbator",
    state: "tamilnadu",
    temp: 39,
  },
  {
    city: "mumbai",
    state: "maharashtra",
    temp: 32,
  },
  {
    city: "mumbai",
    state: "maharashtra",
    temp: 32,
  },
  {
    city: "delhi",
    state: "delhi",
    temp: 24,
  },
  {
    city: "kolkata",
    state: "west bengal",
    temp: 28,
  }
];

const result = arr.reduce((all, cur) => { 
  if (
    all.findIndex((c) => c.city === cur.city && c.state === cur.state) < 0 &&
    cur.state !== cur.city && 
    cur.temp < 40
  ) {
    all.push(cur);
  }

  return all;
}, []);

console.log(result);