add hw2

node_modules/lodash-es/before.js

@@ -0,0 +1,40 @@
+import toInteger from './toInteger.js';
+
+/** Error message constants. */
+var FUNC_ERROR_TEXT = 'Expected a function';
+
+/**
+ * Creates a function that invokes `func`, with the `this` binding and arguments
+ * of the created function, while it's called less than `n` times. Subsequent
+ * calls to the created function return the result of the last `func` invocation.
+ *
+ * @static
+ * @memberOf _
+ * @since 3.0.0
+ * @category Function
+ * @param {number} n The number of calls at which `func` is no longer invoked.
+ * @param {Function} func The function to restrict.
+ * @returns {Function} Returns the new restricted function.
+ * @example
+ *
+ * jQuery(element).on('click', _.before(5, addContactToList));
+ * // => Allows adding up to 4 contacts to the list.
+ */
+function before(n, func) {
+  var result;
+  if (typeof func != 'function') {
+    throw new TypeError(FUNC_ERROR_TEXT);
+  }
+  n = toInteger(n);
+  return function() {
+    if (--n > 0) {
+      result = func.apply(this, arguments);
+    }
+    if (n <= 1) {
+      func = undefined;
+    }
+    return result;
+  };
+}
+
+export default before;