从数组中删除重复项Javascript [重复]

This question already has an answer here:

这个问题在这里已有答案：

Get all non-unique values (i.e.: duplicate/more than one occurrence) in an array 61 answers
获取阵列61答案中的所有非唯一值（即：重复/多次出现）

I'm looking for an easy way of removing a duplicate value from an array. I figured out how to detect if there is a duplicate or not, just I don't know how to "push" it from the value. For example, if you go to the link provided, and then type, "abca" (press return/enter key after each letter).. it will alert "duplicate!"

我正在寻找一种从数组中删除重复值的简单方法。我想出了如何检测是否有重复，只是我不知道如何从值中“推”它。例如，如果您转到提供的链接，然后键入“abca”（在每个字母后按回车键/输入键）..它将提醒“重复！”

But I also want to figure out how to remove that duplicate from the textarea?

但我还想弄清楚如何从textarea中删除该副本？

http://jsfiddle.net/P3gpp/

This is the part that seems to not be working ::

这是似乎无法正常工作的部分::

sort = sort.push(i);
textVal = sort;
return textVal;

6 个解决方案

#1

Why do it the hard way, it can be done more easily using javascript filter function which is specifically for this kind of operations:

为什么这么难，可以使用专门针对这种操作的javascript过滤功能更轻松地完成：

var arr = ["apple", "bannana", "orange", "apple", "orange"];

arr = arr.filter( function( item, index, inputArray ) {
           return inputArray.indexOf(item) == index;
    });


---------------------
Output: ["apple", "bannana", "orange"]

#2

These are the functions I created/use for removing duplicates:

这些是我创建/用于删除重复项的函数：

var removeDuplicatesInPlace = function (arr) {
    var i, j, cur, found;
    for (i = arr.length - 1; i >= 0; i--) {
        cur = arr[i];
        found = false;
        for (j = i - 1; !found && j >= 0; j--) {
            if (cur === arr[j]) {
                if (i !== j) {
                    arr.splice(i, 1);
                }
                found = true;
            }
        }
    }
    return arr;
};

var removeDuplicatesGetCopy = function (arr) {
    var ret, len, i, j, cur, found;
    ret = [];
    len = arr.length;
    for (i = 0; i < len; i++) {
        cur = arr[i];
        found = false;
        for (j = 0; !found && (j < len); j++) {
            if (cur === arr[j]) {
                if (i === j) {
                    ret.push(cur);
                }
                found = true;
            }
        }
    }
    return ret;
};

So using the first one, this is how your code could look:

因此，使用第一个，这是您的代码的外观：

function cleanUp() {
    var text = document.getElementById("fld"),
        textVal = text.value,
        array;

    textVal = textVal.replace(/\r/g, " ");
    array = textVal.split(/\n/g);

    text.value = removeDuplicatesInPlace(array).join("\n");
}

DEMO: http://jsfiddle.net/VrcN6/1/

演示：http：//jsfiddle.net/VrcN6/1/

#3

Based on user2668376 solution, this will return a new array without duplicates.

基于user2668376解决方案，这将返回一个没有重复的新数组。

Array.prototype.removeDuplicates = function () {
    return this.filter(function (item, index, self) {
        return self.indexOf(item) == index;
    });
};

After that you can do:

之后你可以这样做：

[1, 3, 3, 7].removeDuplicates();

Result will be; [1, 3, 7].

结果将是; [1,3,7]。

#4

You can use Array.reduce() to remove the duplicates. You need a helper object to keep track of how many times an item has been seen.

您可以使用Array.reduce（）删除重复项。您需要一个辅助对象来跟踪项目被查看的次数。

function cleanUp() 
{
    var textBox = document.getElementById("fld"),
    array = textBox.value.split(/\r?\n/g),
    o = {},
    output;

    output = array.reduce(function(prev, current) {
        var key = '$' + current;

        // have we seen this value before?
        if (o[key] === void 0) {
            prev.push(current);
            o[key] = true;
        }

        return prev;
    }, []);

    // write back the result
    textBox.value = output.join("\n");
}

The output of the reduce() step can be used directly to populate the text area again, without affecting the original sort order.

reduce（）步骤的输出可以直接用于再次填充文本区域，而不会影响原始排序顺序。

Demo

演示

#5

You can do this easily with just an object:

只需一个对象即可轻松完成此操作：

function removeDuplicates(text) {
    var seen = {};
    var result = '';

    for (var i = 0; i < text.length; i++) {
        var char = text.charAt(i);

        if (char in seen) {
            continue;
        } else {
            seen[char] = true;
            result += char;
        }
    }

    return result;
}

function cleanUp() {
    var elem = document.getElementById("fld");

    elem.value = removeDuplicates(elem.value);
}

#6

      arr3 = [1, 2, 3, 2, 4, 5];

      unique = [];

   function findUnique(val)
  {
   status = '0';
   unique.forEach(function(itm){

      if(itm==val)
      { 
      status=1;
      }

              })
 return status;
 }

 arr3.forEach(function(itm){

  rtn =  findUnique(itm);
  if(rtn==0)
  unique.push(itm);


  });

  console.log(unique);  // [1, 2, 3, 4, 5]

#1