如何統計變量在javascript數組中重複的次數？

如何獲取數組成員及其重複次數（重複次數）？如何統計變量在javascript數組中重複的次數？

目前，我有這個劇本

//COUNT VAL 
var curr = ''; 
var previous = ''; 
var arr = new Array(); 
var sorted = count.sort(); 
for(var c=0; c < sorted.length; c++){ 
if(sorted[c] != ''){ 
if(sorted[c] != curr){ 
var repeat = 1; 
arr[sorted[c]] = repeat; 
curr = sorted[c]; 
} 
else if(sorted[c] == curr){ 
repeat++; 
} 
} 
} 
alert(JSON.stringify(arr));

數組的值「計數」是（我使用JSON.stringify）：

[" 2"," 2"," 2","1","1","1","1","1","1","1","1","1","1",null,null,null,null,null,null,null,null,null,null,null,null,null]

我希望我的腳本來顯示什麼？（IM期待它返回一個數組）

[1: 10, 2: 3]

（X：Y）x是數量，y是次重複它的數量。

我能得到什麼？

[null,1,1]

來源

2012-07-09 JohnSmith

您預期的結果看起來像一個對象文本，但方括號括起來，這使它看起來像一個數組。 – Jamiec 2012-07-09 07:26:24

對不起，如果它令人困惑。我試圖讓一個數組。 – JohnSmith 2012-07-09 07:33:39

這會給你的總結，忽略空值

var collection = [" 2"," 2"," 2","1","1","1","1","1","1","1","1","1","1",null,null,null,null,null,null,null,null,null,null,null,null,null]; 

var summary = collection.reduce(function(a, b) { 
    var tmp = parseInt(b) 
    if (!isNaN(tmp)) { 
     if (!a[tmp]) { 
      a[tmp] = 0; 
     } 
     a[tmp]++; 
    } 
    return a; 
}, {}); 

console.log(summary);

來源

2012-07-09 07:38:36

謝謝你的答案，並刪除空值！ – JohnSmith 2012-07-09 07:47:43

var a = [" 2"," 2"," 2","1","1","1","1","1","1","1","1","1","1",null,null,null,null,null,null,null,null,null,null,null,null,null]; 

var counts = a.reduce(function(obj, cur){ 
    if(!obj[cur]) { 
     obj[cur] = 0; 
    } 
    obj[cur]++; 
    return obj; 
}, {});

結果

2: 3 
1: 10 
null: 13

來源

2012-07-09 07:26:50 Esailija

使用你的代碼，

修改你的循環這樣，

for(var c=0; c < sorted.length; c++){ 
if(sorted[c] != ''){ 
    if(arr[sorted[c]]){ 
     var count = arr[sorted[c]]; 
     count++; 
     arr[sorted[c]] = count; 
    } 
    else{ 
     arr[sorted[c]] = 1; 
    } 
} 
}

來源

2012-07-09 07:33:22

不知道它的最佳的解決方案，但它的工作原理，並保存輸出數組。

var arr = [" 2"," 2"," 2","1","1","1","1","1","1","1","1","1","1",null,null,null,null,null,null,null,null,null,null,null,null,null]; 

var obj = {}; 
var final = []; 
var count = 0; 
for(var i=0,len=arr.length;i<len;i++){ 
    if(arr[i] in obj){ 
    final[obj[arr[i]]] ++; 
    } 
    else{ 
    obj[arr[i]] = count; 
    final[count] = 1; 
    count++; 
    } 
} 

console.log(final);

來源

2012-07-09 07:47:18 Jashwant

試試這個：

var repeated = function repeated(arr){ 
       var res = {}; 
       for(index in arr){ 
        var x = arr[index]; 
        if(!res.hasOwnProperty(x)) 
         res[x] = 0;  
        res[x]++; 
       } 
       return res; 
      }

來源

2012-07-09 08:18:47 Vovochka

如何統計變量在javascript數組中重複的次數？

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