用于确定数组是否包含值的javascript函数[重复]

Question

第一次测试我得到“假”，第二次测试我得到“真”。我想创建一个将评估这些值的函数。我以为我在函数中正确执行了我的代码，但我没有得到我想得到的东西。我不明白我在这里做错了什么。任何帮助将不胜感激。谢谢。

// - Given the arrayOfNames, determine if the array contains the given name.
// - If the array contains the name, return true.  If it does not, return false.
// - Hint: Use a loop to "iterate" through the array, checking if each name matches the name parameter.
// 
// Write your code here ????

function contains(arrayOfNames, name) {
  for (index = 0; index < arrayOfNames.length; index++) {
    if (arrayOfNames[index] === name) {
      return true;
    } else {
      return false;
    }
  }

}

//  -------TESTS---------------------------------------------------------------
//  Run these commands to make sure you did it right. They should all be true.
console.log("-----Tests for Exercise Five-----");
console.log("* Returns true when the array contains the name.");
console.log(contains(["bob", "nancy", "john", "shawnie", "waldo", "shaquon", "julie"], "nancy") === true);
console.log("* Returns false when the name is not in the array");
console.log(contains(["bob", "nancy", "john", "shawnie", "waldo", "shaquon", "julie"], "fred") === false);

Answer 1

仅当数组不包含 name 时才返回 false。

您要做的是，如果找到match，它将返回true，但一旦找不到匹配项arrayOfNames[index] === name)，它将返回false。

在你的第一个例子中：假设i=0，第一个元素是bob。所以arrayOfNames[index] 是bob 而你要搜索的name 是nancy。所以当它匹配它们时它不相等，所以它会返回false。

function contains(arrayOfNames, name) {
  for (let index = 0; index < arrayOfNames.length; index++) {
    if (arrayOfNames[index] === name) {
      return true;
    }
  }
  return false;
}

//  -------TESTS---------------------------------------------------------------
//  Run these commands to make sure you did it right. They should all be true.
console.log("-----Tests for Exercise Five-----");
console.log("* Returns true when the array contains the name.");
console.log(
  contains(
    ["bob", "nancy", "john", "shawnie", "waldo", "shaquon", "julie"],
    "nancy"
  ) === true
);
console.log("* Returns false when the name is not in the array");
console.log(
  contains(
    ["bob", "nancy", "john", "shawnie", "waldo", "shaquon", "julie"],
    "fred"
  ) === false
);