1药蜻、利用ES6方法 set
var arr = [1,2,3,3,3,3,4,4,5,6,7]
function unique(arr) {
return Array.from(new Set(arr))
}
console.log(unique(arr)); // => [ 1, 2, 3, 4, 5, 6, 7 ]
2御毅、for循環(huán) splice去重 去重
var arr = [1,2,3,3,3,3,4,4,5,6,7]
function unique(arr) {
for (var i = 0; i < arr.length; i++) {
for (var j = i+1; j < arr.length; j++) {
if (arr[i] === arr[j]) {
arr.splice(j,1);
j--
}
}
}
return arr
}
console.log(unique(arr)); // => [ 1, 2, 3, 4, 5, 6, 7 ]
3轧抗、利用indexOf去重
var arr = [1,2,3,3,3,3,4,4,5,6,7]
function unique(arr) {
const array = []
for(const x of arr) {
if (array.indexOf(x) === -1) {
array.push(x)
}
}
return array
}
console.log(unique(arr)); // => [ 1, 2, 3, 4, 5, 6, 7 ]
4、...new Set(arr)
var arr = [1,2,3,3,3,3,4,4,5,6,7]
console.log([...new Set(arr)]);// => [ 1, 2, 3, 4, 5, 6, 7 ]
5疾忍、利用sort()方法
var arr = [1, 2, 3, 3, 3, 3, 4, 4, 5, 6, 7]
function unique(arr) {
arr = arr.sort()
var array = [arr[0]];
for (var i = 1; i < arr.length; i++) {
if (arr[i] !== arr[i-1]) {
array.push(arr[i])
}
}
return array
}
console.log(unique(arr)); // => [ 1, 2, 3, 4, 5, 6, 7 ]
