文字数測定[改]

StrCount.js

  // 文字数測定
  var StrCount = {
    //改行
    line: 1,
    //全角
    em: 1,
    //半角
    em_half: 0.5,
    //4バイト文字
    surrogate: 1,
    //文字列
    str: "",

    surrogate_count: function(){
      //サロゲートベア(４バイト対応) 
      var count = this.str.split( /[\uD800-\uDBFF][\uDC00-\uDFFF]/g ).length - 1;
      if (count > 0){
          count = count * this.surrogate;
      }
      
      this.str = this.str.replace( /[\uD800-\uDBFF][\uDC00-\uDFFF]/g, '' );
      
      return count;
    },
    
    str_count_sum: function(str){
      this.str = str;
      surrogate_count = this.surrogate_count();
      
      var count = 0;
      
      for (var i = 0, len = this.str.length; i < len; i++) {
          var c  = this.str.charCodeAt(i);
          count += this.charcode(c);
      }
      
      count = count + surrogate_count;
      return count;
    },
    
    charcode: function(c){
      count = 0;

      if (c == 10 || c == 13){
          //改行(\r||\n)
          count = this.line;
      } else if ((c >= 0x0 && c < 0x81) || (c == 0xf8f0) || (c >= 0xff61 && c < 0xffa0) || (c >= 0xf8f1 && c < 0xf8f4)) {
          //半角
          count = this.em_half;
      } else {
          //全角
          count = this.em;
      }

      return count;
    }
  };