const list = [
{
name:'aa',
value:'fffff'
},
{
name:'bb',
value:'vvvvvvv'
},
{
name:'cc',
value:'vvvvvvv'
},
{
name:'aa',
value:'bbbbbbbbb'
},
{
name:'dd',
value:'nnnnnnn'
},
{
name:'dd',
value:'mmmmmmmmmmm'
},
]
let arr = []
for (let i = 0; i < list.length; i++) {
const e = list[i];
arr.push(e.name)
}
const listSame = arr.filter((e, i) => arr.indexOf(e) !== arr.lastIndexOf(e) && arr.indexOf(e) === i)
console.log(listSame); //['aa','dd']