我们如何将函数的一个特定变量作为回调传递？

function outerFunction() {
  var specialVariable = "特定变量";
  
  function innerFunction() {
    console.log(specialVariable);
  }
  
  return innerFunction;
}

var callback = outerFunction();
callback(); // 输出 "特定变量"

function callbackFunction(specialVariable) {
  console.log(specialVariable);
}

function performOperation(callback) {
  var variableToPass = "特定变量";
  callback(variableToPass);
}

performOperation(callbackFunction); // 输出 "特定变量"

function callbackFunction() {
  console.log(this.specialVariable);
}

var specialObject = {
  specialVariable: "特定变量"
};

var boundCallback = callbackFunction.bind(specialObject);
boundCallback(); // 输出 "特定变量"