JS_Workbook/array.js at main · Dharamsen/JS_Workbook · GitHub

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// Remove duplicate values from an array.
// let arr = [1,1,1,1,2,2,2,2,3,3,3,3,4,4,4,5,5,5,6,6,6,7,8,7,8,7,9,9,9,9]
//  let ans = [...new Set(arr)]
//  console.log(ans);

 //---------------------------------------------------------------------------------

//  Find the second largest number in an array.
// var arr =[10,9,8,7,8,7,99,8]
// // uniques values nikallo
// // sort aray from descending order
//  let ans = [...new Set(arr)]
// //  console.log(ans);
// let sortedArr = ans.sort(function(a,b)
// {
//     return b-a;
// })
//  console.log(sortedArr[1]);

//  -----------------------------------------------------------------------------------------------------------------------------

// . Sort an array in descending order

// let arr = [10,8,7,4,5,9,6,3,55,11,48,96,5,47,22,56]
// let ans = arr.sort(function(a,b){
//     return b-a;
// })
// console.log(ans);

// --------------------------------------------------------------------------------------------------------
// Reverse an array without using .reverse().

// let arr = [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16]

// let arr2 = [];
// for (let i = arr.length-1;i>=0 ;i--) {
//     arr2.push(arr[i])

// }

// -------------------------------------------------------------------------------------------------------


// Find the most frequent element in an array. // sabse zyada baar kaun aaya hai

let arr = [1,1,2,2,3,3,4,4,4,5,5,6,6,6,6,7,7,7,8,8,8,9,9,9]
 let obj = {}

//  let ans = arr.forEach(function(val){
//     obj[val] === undefined ? (obj[val]=1) : obj[val]++;

//  })
 let ans = arr.forEach(function(val)
{
    if(obj[val]===undefined)
    {
        obj[val]=1;
    }
    else{
        obj[val]++;
    }
})