记忆

Fri, Nov 29, 2019

源码

//在vue中使用了一个cached存储站来实现记忆

 /**
   * Create a cached version of a pure function.
   */
  function cached (fn) {
    var cache = Object.create(null);
    return (function cachedFn (str) {
      var hit = cache[str];
      return hit || (cache[str] = fn(str))
    })
  }

  /**
   * Camelize a hyphen-delimited string.
   */
  var camelizeRE = /-(\w)/g;
  var camelize = cached(function (str) {
    return str.replace(camelizeRE, function (_, c) { return c ? c.toUpperCase() : ''; })
  });

  /**
   * Capitalize a string.
   */
  var capitalize = cached(function (str) {
    return str.charAt(0).toUpperCase() + str.slice(1)
  });

  /**
   * Hyphenate a camelCase string.
   */
  var hyphenateRE = /\B([A-Z])/g;
  var hyphenate = cached(function (str) {
    return str.replace(hyphenateRE, '-$1').toLowerCase()
  });

为什么创建空对象用了Object.create(null)