Count the number of occurrences of a character in a string in Javascript

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礼貌的吻别
礼貌的吻别 2020-11-22 02:33

I need to count the number of occurrences of a character in a string.

For example, suppose my string contains:

var mainStr = \"str1,str2,str3,str4\";         


        
30条回答
  •  南笙
    南笙 (楼主)
    2020-11-22 03:04

    Performance of Split vs RegExp

    var i = 0;
    
    var split_start = new Date().getTime();
    while (i < 30000) {
      "1234,453,123,324".split(",").length -1;
      i++;
    }
    var split_end = new Date().getTime();
    var split_time = split_end - split_start;
    
    
    i= 0;
    var reg_start = new Date().getTime();
    while (i < 30000) {
      ("1234,453,123,324".match(/,/g) || []).length;
      i++;
    }
    var reg_end = new Date().getTime();
    var reg_time = reg_end - reg_start;
    
    alert ('Split Execution time: ' + split_time + "\n" + 'RegExp Execution time: ' + reg_time + "\n");

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