嵌套for循环显示重复输出

Question

我一直在获取输出，但它是 amount.Like 的两倍，例如，如果所需的输出是 SUGAR.The，程序将显示

SUGAR
SUGAR

我有办法解决这个问题吗？我实际上是在使用嵌套的 for 循环来遍历 objects.Below 的数组是嵌套的 for 循环的代码

for(var i=0; i<ingredientList.length; i++){

     for(var j=0; j<this.objUser.length; j++){

          len = this.objUser.length;

        userAllergyDetails.push(this.objUser[j].userAllergies);

       for(var k=0; k<len; k++){  //matching starts

         if(ingredientList[i] == this.objUser[j].userAllergies.toUpperCase()){

           console.log('match');
           unSafeResult.push(ingredientList[i]);
           console.log(unSafeResult);
         }

       }


     }

   }
    console.log(userAllergyDetails);
   console.log(userAllergyDetails.length);
   console.log(this.objUser);

  }

以上代码的输出是

ingredient list (26) ["INGREDIENTS↵WHEAT FLOUR", "SUGAR", "CHOCOLATE LIQUOR", "HYDROGENATED VEGETABLE↵OIL", "SAL FAT", "SHEA BUTTER", "RAPESEED OIL", "PALM OIL", "SUNFLOWER OIL", "WHOLE MILK↵POWDER", "SHORTENING", "COCOA BUTTER", "SALT", "BUTTER", "YEAST", "EMULSIFIER", "POLYGLYCEROLPOLYRICINOLEANTE", "SOY LECITHIN", "ARTIFICIAL FLAVOR", "TRISODIUMPHOSPHATE", "LEAVENING", "SODIUM BICARBONATE", "CONTAINS: MILK", "WHEAT", "SOYBEANS and SHEANUT", "Manufactured in a facility that uses↵EGGS and PEANUTS"]
 match
main.js:41963 ["SUGAR"]0: "SUGAR"1: "SUGAR"length: 2__proto__: Array(0)
main.js:41961 match
main.js:41963 (2) ["SUGAR", "SUGAR"]0: "SUGAR"1: "SUGAR"length: 2__proto__: Array(0)
main.js:41968 data retrieve from object (52) ["Oil", "Sugar", "Oil", "Sugar", "Oil", "Sugar", "Oil", "Sugar", "Oil", "Sugar", "Oil", "Sugar", "Oil", "Sugar", "Oil", "Sugar", "Oil", "Sugar", "Oil", "Sugar", "Oil", "Sugar", "Oil", "Sugar", "Oil", "Sugar", "Oil", "Sugar", "Oil", "Sugar", "Oil", "Sugar", "Oil", "Sugar", "Oil", "Sugar", "Oil", "Sugar", "Oil", "Sugar", "Oil", "Sugar", "Oil", "Sugar", "Oil", "Sugar", "Oil", "Sugar", "Oil", "Sugar", "Oil", "Sugar"]

这是我要遍历的对象

Object
0:
resultUnsafe
:
Array(0)
resultWarning
:
Array(0)
userAllergies
:
"Oil"
userName
:
"Dad"
__proto__
:
Object
1
:
Object
resultUnsafe
:
Array(0)
resultWarning
:
Array(0)
userAllergies
:
"Sugar"
userName
:
"Mum"

如对象所示，只有 2 个 userAllergies，这意味着长度为 2，但为什么在控制台中显示 52？我如何确保只有 SUGAR 被推送到数组？

Answer 1

为了使您的代码更好，您应该考虑使用更具描述性的索引变量：

for (var ingredientIndex = 0; ingredientIndex < ingredientList.length; ingredientIndex ++)

打字时间更长，但更容易调试像您遇到的细微问题

这是有效的版本，更易于阅读：

// Loop through the ingredients
for (var ingredientIndex = 0; ingredientIndex < ingredientList.length; ingredientIndex++) {

    // For each ingredient, check each user to see if they are allergic
    for (var userIndex = 0; userIndex < objUser.length; userIndex++) {

        // Loop through each user's allergies
        for (var allergyIndex = 0; allergyIndex < objUser[userIndex].userAllergies.length; allergyIndex++) {
            if (ingredientList[ingredientIndex] == objUser[userIndex].userAllergies[allergyIndex].toUpperCase()) {
                unSafeResult.push(ingredientList[ingredientIndex]);
            }
        }
    }
}

嵌套for循环显示重复输出

Nested for loop display duplicated output

javascript

nested-loops