如何添加 javascript

Question

while (studentRecords.readNextRecord()) {
    currentZipCode       =  studentRecords.getStudentZipCode();
    currentGender        =  studentRecords.getStudentGender();

    if (currentZipCode === FIRST_ZIPCODE) {
        if (currentGender === "M")
        document.write("53711: Males: " + currentGender + "<br />");
    }
}

如何将所有 M 加在一起生成 53711：男：5??

Answer 1

保持 运行 计数，在完成循环之前不要输出总数。

var males = 0;

while (studentRecords.readNextRecord()) {
  currentZipCode       =  studentRecords.getStudentZipCode();
  currentGender        =  studentRecords.getStudentGender();

  if (currentZipCode === FIRST_ZIPCODE) {
    if (currentGender === "M") {
      ++males;
    }
  }
}

document.write("53711: Males: " + males + "<br />");