Question

184

Remove duplicate values from an array of objects in javascript

rated 0 times [ 186] [ 2] / answers: 1 / hits: 87093 / 7 Years ago, tue, august 1, 2017, 12:00:00

i have an array of objects like this:

arr = [

    {label: Alex, value: Ninja},

    {label: Bill, value: Op},

    {label: Cill, value: iopop}

]

This array is composed when my react component is rendered. The i user Array.prototype.unshift for adding a desired element in the top of my array.
So i write arr.unshift({label: All, value: All}). When my component first rendered my array is successfully created as i desire. But when i rerender it it shows me the array with the value {label: All, value: All} as duplicate. To be more specific it is shown something like this:

arr = [

    {label: All, value: All},

    {label: All, value: All},

    {label: Alex, value: Ninja},

    {label: Bill, value: Op},

    {label: Cill, value: iopop}

]

How can i fix this? I tried the methods described in a specific topic here but it didn't work

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dylondaytond

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answered 7 Years ago kristopher · Accepted Answer

You can use array#reduce and array#some.

const arr = [

    {label: 'All', value: 'All'},

    {label: 'All', value: 'All'},

    {label: 'Alex', value: 'Ninja'},

    {label: 'Bill', value: 'Op'},

    {label: 'Cill', value: 'iopop'}

]



var result = arr.reduce((unique, o) => {

    if(!unique.some(obj => obj.label === o.label && obj.value === o.value)) {

      unique.push(o);

    }

    return unique;

},[]);

console.log(result);