javascript function-优快云博客

本文探讨了JavaScript中函数断言的使用方法，包括如何验证函数定义、名称及作用域，通过实例展示了如何实现断言来确保代码的正确性和一致性。

function assert(value1, value2) {
  if (value1) {
    console.log(value2);
  }
}

function isNimble() {
  return true;
}
assert(typeof window.isNimble === "function", "is isNimbl() defined");
assert(isNimble.name === "isNimble", "isNimble() has a name");

var canFly = function() {
  return true;
};
assert(typeof window.canFly === "function", "canFly() defined");
assert(canFly.name === "", "canFly() has no name");

window.isDeadly = function() {
  return true;
};
assert(typeof window.isDeadly === "function", "isDeadly() defined");
assert(isDeadly.name === "isDeadly", "isDeadly() has a name");

function outer() {
  assert(typeof inner === "function", "inner() in scope before declaration");
  function inner () {}
  assert(typeof inner === "function", "inner() in scope after declaration");
  assert(window.inner === undefined, "inner() not in global scope");
}

outer();
assert(window.inner === undefined, "inner() stilll not in global scope");


window.wieldsSword = function swingsSword() { return true; };
assert(window.wieldsSword.name === 'swingsSword', "wieldSword's real name is swingsSword");

"is isNimbl() defined"
"isNimble() has a name"
"canFly() defined"
"canFly() has no name"
"isDeadly() defined"
"inner() in scope before declaration"
"inner() in scope after declaration"
"inner() not in global scope"
"inner() stilll not in global scope"
"wieldSword's real name is swingsSword"

转载于:https://www.cnblogs.com/Iwillknow/p/4030957.html