Typescript 仅当定义了值时才按值筛选数组

发布于10月09日

How can I peform this filter but only check each condition if the value is not undefined?
For example, if taxId is undefined I want to ignore it instead of filtering by it.

this.subAgencies = demoSubAgencies.filter(function(subAgency) {
  return subAgency.subAgencyName == agencyName
    && subAgency.taxId == taxId
    && subAgency.accountNumber == accountNumber;
});

推荐答案

您可以try 基于值的存在动态构建筛选条件.您可以使用&&运算符链接到条件，但只有在相应的值不是undefined时才包括条件.

下面是一个如何做到这一点的例子:

this.subAgencies = demoSubAgencies.filter(function(subAgency) {
  let condition = true; // Start with a true condition

  // Check if agencyName is defined, and if so, include it in the condition
  if (agencyName !== undefined) {
    condition = condition && subAgency.subAgencyName == agencyName;
  }

  // Check if taxId is defined, and if so, include it in the condition
  if (taxId !== undefined) {
    condition = condition && subAgency.taxId == taxId;
  }

  // Check if accountNumber is defined, and if so, include it in the condition
  if (accountNumber !== undefined) {
    condition = condition && subAgency.accountNumber == accountNumber;
  }

  return condition;
});