如何判断newField中new_field_name值是否存在于mapping的value属性中

需求：验证newField数组内每个对象的new_field_name属性值，是否存在于mapping数组对象的value属性集合中。

方法一：用Set优化查找性能（推荐大数据量场景） #

先把mapping中的所有value提取存入Set（Set的查找时间复杂度为O(1)，比数组遍历更高效），再遍历newField做存在性检查：

let mapping =  [ { "value": "title", "text": "Do Not Import", "custom": null }, { "value": "short_message", "text": "Do Not Import", "custom": null }, { "value": "url", "text": "Do Not Import", "custom": null }, { "value": "campaign_id", "text": "Do Not Import", "custom": null }, { "value": "aff_code", "text": "Do Not Import", "custom": null }, { "value": "campaign_url", "text": "Do Not Import", "custom": null }, { "value": "other_data", "text": "Do Not Import", "custom": null }, { "value": "product_id", "text": "Do Not Import", "custom": null }, { "value": "created_at", "text": "Do Not Import", "custom": null }, { "value": "product_active", "text": "Do Not Import", "custom": null }, { "value": "brand", "text": "Do Not Import", "custom": null }, { "value": "old_price", "text": "Do Not Import", "custom": null }, { "value": "subcategory", "text": "Do Not Import", "custom": null }, { "value": "category", "text": "Do Not Import", "custom": null }, { "value": "price", "text": "Do Not Import", "custom": null }, { "value": "widget_name", "text": "Do Not Import", "custom": null }, { "value": "campaign_name", "text": "Do Not Import", "custom": null }, { "value": "image_urls", "text": "Do Not Import", "custom": null }, { "value": "description", "text": "Do Not Import", "custom": null } ]; 
let newField = [ { "new_field_name": "one ", "new_field_value": "" }, { "new_field_name": "url", "new_field_value": "" } ];

// 提取mapping的所有value到Set
const mappingValueSet = new Set(mapping.map(item => item.value));

// 遍历newField执行检查
newField.forEach(field => {
  // 可选：去除字段名首尾空格，避免空格导致的匹配失败
  const cleanedFieldName = field.new_field_name.trim();
  const isExists = mappingValueSet.has(cleanedFieldName);
  
  // 输出检查结果
  console.log(`字段「${field.new_field_name}」是否存在于mapping中：${isExists}`);
  
  // 可将结果附加到原对象，方便后续使用
  field.isExistsInMapping = isExists;
});

// 查看处理后的newField数组
console.log(newField);

方法二：直接遍历检查（适合小数据量场景） #

如果数据量不大，可直接用Array.some()遍历mapping做匹配，代码更简洁：

let mapping =  [ { "value": "title", "text": "Do Not Import", "custom": null }, { "value": "short_message", "text": "Do Not Import", "custom": null }, { "value": "url", "text": "Do Not Import", "custom": null }, { "value": "campaign_id", "text": "Do Not Import", "custom": null }, { "value": "aff_code", "text": "Do Not Import", "custom": null }, { "value": "campaign_url", "text": "Do Not Import", "custom": null }, { "value": "other_data", "text": "Do Not Import", "custom": null }, { "value": "product_id", "text": "Do Not Import", "custom": null }, { "value": "created_at", "text": "Do Not Import", "custom": null }, { "value": "product_active", "text": "Do Not Import", "custom": null }, { "value": "brand", "text": "Do Not Import", "custom": null }, { "value": "old_price", "text": "Do Not Import", "custom": null }, { "value": "subcategory", "text": "Do Not Import", "custom": null }, { "value": "category", "text": "Do Not Import", "custom": null }, { "value": "price", "text": "Do Not Import", "custom": null }, { "value": "widget_name", "text": "Do Not Import", "custom": null }, { "value": "campaign_name", "text": "Do Not Import", "custom": null }, { "value": "image_urls", "text": "Do Not Import", "custom": null }, { "value": "description", "text": "Do Not Import", "custom": null } ]; 
let newField = [ { "new_field_name": "one ", "new_field_value": "" }, { "new_field_name": "url", "new_field_value": "" } ];

newField.forEach(field => {
  const cleanedFieldName = field.new_field_name.trim();
  const isExists = mapping.some(item => item.value === cleanedFieldName);
  
  console.log(`字段「${field.new_field_name}」是否存在于mapping中：${isExists}`);
  field.isExistsInMapping = isExists;
});

console.log(newField);

示例输出 #

运行上述代码后，控制台会输出：

字段「one 」是否存在于mapping中：false
字段「url」是否存在于mapping中：true

内容的提问来源于stack exchange，提问作者Shibbir