JavaScript数字不区分大小写

Question

我必须计算每个字母出现在字符串中的次数。 不区分大小写。
例如：
VAR STR = “aaaAAAbbB”
将打印 “A：6，B：3”
这是我有但它计数小写和大写作为单独的。

 var string = document.getElementById("text").value 
     var counts = {}; 
     var ch, index, length, count; 
     for (index = 0, length = string.length; index < length; index++) 
     { 
      ch = string.charAt(index); 
      count = counts[ch]; 
      counts[ch] = count ? count + 1 : 1; 
     } 
     for (ch in counts) 
     { 
      console.log(ch+" count: "+counts[ch]); 
     } 

Answer 1

你可以在字符更改为upper或lower情况进行计数。

ch = string.charAt(index).toUpperCase(); 
//      ^^^^^^^^^^^^^^ 

var string = "aaaAAAbbB"; 
 
var counts = {}; 
 
var ch, index, length, count; 
 
for (index = 0, length = string.length; index < length; index++) { 
 
    ch = string.charAt(index).toUpperCase(); 
 
    count = counts[ch]; 
 
    counts[ch] = count ? count + 1 : 1; 
 
} 
 
for (ch in counts) { 
 
    console.log(ch + " count: " + counts[ch]); 
 
}

紧凑风格

var string = "aaaAAAbbB", 
 
    counts = {}; 
 

 
string.split('').forEach(function (c) { 
 
    counts[c.toUpperCase()] = (counts[c.toUpperCase()] || 0) + 1; 
 
}); 
 

 
console.log(counts);

Answer 2

为了解决你的问题，我会简单地使用

string.toLowerCase(); 

然后你可以计算每个字符。

我修改你的代码：

var string = document.getElementById("text").value.toLowerCase(); 
    var counts = {}; 
    var ch, index, length, count; 
    for (index = 0, length = string.length; index < length; index++) 
    { 
     ch = string.charAt(index); 
     count = counts[ch]; 
     counts[ch] = count ? count + 1 : 1; 
    } 
    for (ch in counts) 
    { 
     console.log(ch+" count: "+counts[ch]); 
    } 

Answer 3

您可以使用.toLowerCase()方法，它改变所有的文本为小写 那么你的代码应该是这样的：

var string = document.getElementById("text").value.toLowerCase() 
    var counts = {}; 
    var ch, index, length, count; 
    for (index = 0, length = string.length; index < length; index++) 
    { 
     ch = string.charAt(index); 
     count = counts[ch]; 
     counts[ch] = count ? count + 1 : 1; 
    } 
    for (ch in counts) 
    { 
     console.log(ch+" count: "+counts[ch]); 
    } 

Answer 4

var str = "aaaAAAbbB"; 
 
var result = {}; 
 
//lowercase so they are all insensative and split to get an array. loop over the array 
 
str.toLowerCase().split('').forEach(function(element, index, array){ 
 
    //if not processed before, perform count 
 
    if (!result[element]) { 
 
    result[element] = array.filter(function(element2){ return element2 === element; }).length; 
 
    } 
 
}); 
 

 
console.log(result);