测试数组：
let arr
= [3, 1, 0, 0, 1, 1, 2, 3, 4, 2, 1, 2, 4, 2, 3, 0, 2, 4, 2, 1, 4, 5, 5, 5, 3
];
先来几个简单的
//数组去重-1
function arrayUniq_1
(arr
){
let o
= {};
for (let i
= 0
; i
<arr.length
; i++
){
var t
= arr
[i
]
if
(typeof o
[t
] !== "undefined"){
arr
[i
] = arr
[arr.length-1
]
arr.length--
;
i--
;;
}
o
[t
] = t
;
}
o
= null
;
return arr
;
}
console.log
("数组除重-1：" + arrayUniq_1
(arr
));
//数组去重0
function arrayUniq0
(arr
) {
let result
= [...new Set
(arr
)]
return result
;
}
console.log
("数组除重0：" + arrayUniq0
(arr
));
//数组去重1
function arrayUniq1
(arr
) {
let result
= arr.filter
((item, index, array
) => {
return array.lastIndexOf
(item
) == index
})
return result
;
}
console.log
("数组除重1：" + arrayUniq1
(arr
));
//数组去重2
function arrayUniq2
(arr
) {
let result
= [];
arr.forEach
(element
=> {
result.indexOf
(element
) == -1
&& result.push
(element
)
});
return result
;
}
console.log
("数组除重2：" + arrayUniq2
(arr
));
//数组去重3
function arrayUniq3
(arr
) {
let obj
= {};
var resultArr
= [];
for (let index
= 0
; index
< arr.length
; index++
) {
if (!(arr
[index
] in obj
)) {
obj
[arr
[index
]] = 0
;
resultArr.push
(arr
[index
]);
}
}
return resultArr
;
}
console.log
("数组除重3：" + arrayUniq3
(arr
));
双层循环不能少
//数组去重4
function arrayUniq4
(arr
) {
var resultArr
= [];
for (let index
= 0
; index
< arr.length
; index++
) {
let j
= 0
;
for (let i
= 0
; i
< arr.length
; i++
) {
if (arr
[index
] == arr
[i
]) {
j++
;
if (j
> 1
) {
delete arr
[i
];
}
}
}
if (arr
[index
] != undefined
) {
resultArr.push
(arr
[index
]);
}
}
return resultArr
;
}
console.log
("数组除重4：" + arrayUniq3
(arr
));
//
for forEach for
...in
.. 两两组合 没意思不写了
//
for forEach for
...in
.. 替换除重1的外部循环
//
for forEach for
...in
.. 替换除重2的外部循环
替换一下1方法
//数组去重5
function arrayUniq5
(arr
) {
let result
= [].filter.call
(arr,
(item, index, array
) => {
return array.lastIndexOf
(item
) == index
})
return result
;
}
console.log
("数组除重5：" + arrayUniq5
(arr
));
//数组去重8
function arrayUniq8
(arr
) {
let result
= [].filter.bind
(arr
)((item, index, array
) => {
return array.lastIndexOf
(item
) == index
})
return result
;
}
console.log
("数组除重8：" + arrayUniq8
(arr
));
//数组去重9
function arrayUniq9
(arr
) {
let result
= [].filter.apply
(arr,
[(item, index, array
) => {
return array.lastIndexOf
(item
) == index
}])
return result
;
}
console.log
("数组除重9：" + arrayUniq9
(arr
));
// 按照 5,8,9 进行替换 你懂得有多少种
替换下外部
//数组去重6
function arrayUniq6
(arr
) {
let obj
= {};
var resultArr
= [];
[].forEach.call
(arr, element
=> {
if (!(element
in obj
)) {
obj
[element
] = 0
;
resultArr.push
(element
);
}
})
return resultArr
;
}
console.log
("数组除重6：" + arrayUniq6
(arr
));
//数组去重7
function arrayUniq7
(arr
) {
let obj
= {};
var resultArr
= [];
[].forEach.bind
(arr, element
=> {
if (!(element
in obj
)) {
obj
[element
] = 0
;
resultArr.push
(element
);
}
})()
return resultArr
;
}
console.log
("数组除重7：" + arrayUniq7
(arr
));
由此推算 … 你懂得(滑稽练)
