茉莉花不能讀取未定義的屬性'長度'

Question

你好我是一個新手到單元測試我寫了一個程序，它需要3個參數兩個romanletters和一個操作符（+， - ，/，*）它應該執行操作，它應該返回在romanLetters的價值是試圖編寫一個單元測試的問題，它說不能讀取未定義的屬性長度我不知道爲什麼發生我的代碼運行良好，雖然。附上我在這裏的代碼

Mainjs文件

var main=function(operand1,operand2,operator) { 
    var concat,number; 
    var operand1=romantonumerals(operand1); 
    var operand2=romantonumerals(operand2); 
    //var operator=operatorconversion(operator); 
    console.log("operand1 "+operand1); 
    console.log("operand2 "+operand2); 
    if(operand1>operand2) { 
     concat=operand1+operator+operand2; 
    } 
    else { 
     concat=operand2+operator+operand1; 
    } 
    number=Math.round(eval(concat)); 
    console.log(number); 
    if(number<500) { 
     result=numeralstoroman(number) 
    } 
    else if(number===0) { 
     result="Make sure its greater than 0"; 
    } 
    else { 
     result="Make sure your number gets less than 500 try with some other romans"; 
    } 
    console.log(result); 
    return result; 
    }; 
    var numeralstoroman=function(number) { 
    var roman="",temp; 
    var ones=function(number) { 
     switch (number) { 
     case 1: 
      roman+="I"; 
      break; 
     case 2: 
      roman+="II"; 
      break; 
     case 3: 
      roman+="III"; 
      break; 
     case 4: 
      roman+="IV"; 
      break; 
     case 5: 
      roman+="V"; 
      break; 
     case 6: 
      roman+="VI"; 
      break; 
     case 7: 
      roman+="VII"; 
      break; 
     case 8: 
      roman+="VIII"; 
      break; 
     case 9: 
      roman+="IX"; 
      break; 
     } 
    }; 
    var twos=function(number) { 
     if(number>=10 && number<20) { 
     roman+="X"; 
     ones(number%10); 
     } 
     else if(number>=20 && number30) { 
     roman+="XX"; 
     ones(number%10); 
     } 
     else if(number>=30 && number<40) { 
     roman+="XXX"; 
     ones(number%10); 
     } 
     else if(number>=40 && number<50) { 
     roman+="XL"; 
     ones(number%10); 
     } 
     else if(number>=50 && number<60) { 
     roman+="L"; 
     ones(number%10); 
     } 
     else if(number>=60 && number<70) { 
     roman+="LX"; 
     ones(number%10); 
     } 
     else if(number>=70 && number<80) { 
     roman+="LXX"; 
     ones(number%10); 
     } 
     else if(number>=80 && number<90) { 
     roman+="LXXX"; 
     ones(number%10); 
     } 
     else if(number>=90 && number<100) { 
     roman+="XC"; 
     ones(number%10); 
     } 
    }; 
    var threes=function(number) { 
     if(number>=100 && number<200) { 
      roman+="C"; 
      if(number%100<10) { 
      ones(number%10); 
      } 
      else { 
      twos(number%100); 
      } 
     } 
     else if(number>=200 && number<300) { 
      roman+="CC"; 
      if(number%100<10) { 
      ones(number%10); 
      } 
      else { 
      twos(number%100); 
      } 
     } 
     else if(number>=300 && number<400) { 
      roman+="CCC"; 
      if(number%100<10) { 
      ones(number%10); 
      } 
      else { 
      twos(number%100); 
      } 
     } 
     else if(number>=400 && number<500) { 
      roman+="CD"; 
      if(number%100<10) { 
      ones(number%10); 
      } 
      else { 
      twos(number%100); 
      } 
     } 
    } 
    if(number<10) { 
     ones(number); 
    } 
    else if(number>=10 && number<100) { 
     twos(number); 
    } 
    else if(number>=100 && number<500) { 
     threes(number); 
    } 
    console.log(roman); 
    return roman; 
    }; 
    var character=function(str) { 
    switch(str) { 
     case "I": 
     return 1 
     case "V": 
     return 5 
     case "X": 
     return 10 
     case "L": 
     return 50 
     case "C": 
     return 100 
     case "D": 
     return 500 
     default: 
     return -1; 
    } 
    } 
    var romantonumerals=function(operand) { 
    var no=0,i=0,char1="",char2=""; 
    while(i<operand.length) { 
     char1=character(operand[i]); 
     if(i+1<operand.length) { 
     char2=character(operand[i+1]); 
     if(char1>=char2) { 
      no+=char1; 
      i++; 
     } 
     else { 
      no=no+(char2-char1); 
      i+=2; 
     } 
     } 
     else { 
     no+=char1; 
     i++; 
     } 
    } 
    return no; 
    }; 
    var ans=main("V","I","+"); 
    console.log(ans); 

JasmineHTML文件

<!DOCTYPE html> 
    <html> 
    <head> 
    <meta charset="utf-8"> 
    <title>Jasmine Spec Runner v2.2.0</title> 

    <link rel="shortcut icon" type="image/png" href="lib/jasmine-2.2.0/jasmine_favicon.png"> 
    <link rel="stylesheet" href="lib/jasmine-2.2.0/jasmine.css"> 

    <script src="lib/jasmine-2.2.0/jasmine.js"></script> 
    <script src="lib/jasmine-2.2.0/jasmine-html.js"></script> 
    <script src="lib/jasmine-2.2.0/boot.js"></script> 

    <!-- include source files here... --> 
    <script src="romtantonumeralstoroman.js"></script> 
    <!-- include spec files here... --> 
    <script src="spec.js"></script> 


    </head> 

    <body> 
    </body> 
    </html> 

茉莉花測試文件

describe("A suite", function() { 
it("contains spec with an expectation", function() { 
    main(); 
    expect(main("V","I","+").toBe("VI")); 
}); 
}); 

的jsfiddle鏈接

https://jsfiddle.net/pLecneto/

Answer 1

問題是你打電話main();沒有任何參數在您的規範。如果操作數是undefined，則在while(i<operand.length)上拋出異常。

，改變你的expect聲明，如：

expect(main("V","I","+")).toBe("VI");