const data = [
{key: 1, classifName: 'ABC', classifId: 1},
{key: 2, classifName: 'BCД', classifId: 2},
{key: 3, classifName: 'СДВ', classifId: 3},
{key: 1, classifName: 'ABC', classifId: 1},
{key: 1, classifName: 'ABC', classifId: 1},
];
const res = [
{key: 1, classifName: 'ABC', classifId: 1},
{key: 2, classifName: 'BCД', classifId: 2},
{key: 3, classifName: 'СДВ', classifId: 3},
];
Object.values([
{key: 1, classifName: 'ABC', classifId: 1},
{key: 2, classifName: 'BCД', classifId: 2},
{key: 3, classifName: 'СДВ', classifId: 3},
{key: 1, classifName: 'ABC', classifId: 1},
{key: 1, classifName: 'ABC', classifId: 1},
].reduce((result, item) => {
result[item.classifId] = item;
return result;
}, {}))