Count number of occurrences for each char in a string

问题:

I want to count the number of occurrences of each character in a given string using JavaScript.

For example:

var str = "I want to count the number of occurances of each char in this string"; 

Output should be:

h = 4; e = 4; // and so on  

I tried searching Google, but didn't find any answer. I want to achieve something like this; order doesn't matter.

回答1:

This is really, really simple in JavaScript (or any other language that supports maps):

// The string var str = "I want to count the number of occurances of each char in this string";  // A map (in JavaScript, an object) for the character=>count mappings var counts = {};  // Misc vars var ch, index, len, count;  // Loop through the string... for (index = 0, len = str.length; index 

Now counts has properties for each character; the value of each property is the count. You can output those like this:

for (ch in counts) {     console.log(ch + " count: " + counts[ch]); } 

回答2:

    function cauta() {          var str = document.form.stringul.value;         str = str.toLowerCase();         var tablou = [];          k = 0;         //cautarea caracterelor unice         for (var i = 0, n = 0; i  -1) {                 ++count;                 pos = str.indexOf(char, ++pos);              }              document.getElementById("rezultat").innerHTML += tablou[i] + ":" + count + '\n';             count = 0;         }         }      } 

This function will put each unique char in array, and after will find the appearances of each char in str. In my Case, i get and put data into

回答3:

This worked well for me :

    function Char_Count(str1) {     var chars = {};     str1.replace(/\S/g, function(l){chars[l] = (isNaN(chars[l]) ? 1 :      chars[l] + 1);});     return chars;   }    var myString = "This is my String";   console.log(Char_Count(myString)); 

回答4:

I am giving you very very simple code.

 // Converts String To Array         var SampleString= Array.from("saleem");          // return Distinct count as a object         var allcount = _.countBy(SampleString, function (num) {             return num;         });          // Iterating over object and printing key and value         _.map(allcount, function(cnt,key){             console.log(key +":"+cnt);         });          // Printing Object         console.log(allcount);

Set the variable to different value and then try...
     

回答5:

 // Converts String To Array         var SampleString= Array.from("saleem");          // return Distinct count as a object         var allcount = _.countBy(SampleString, function (num) {             return num;         });          // Iterating over object and printing key and value         _.map(allcount, function(cnt,key){             console.log(key +":"+cnt);         });          // Printing Object         console.log(allcount);

Set the variable to different value and then try...
     

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