Question

函数keywordusage应该以布尔数组的形式返回文本中存在哪些关键字，如：array: [true, false, false]。基于函数的第二个参数。现在，我只能返回true值，当案例为false时，我不知道如何返回false值。代码如下。输出应为 [true，false，false]

    {function keywordusage(str,strArr){
var count = [];
var found = true;
var notfound = false;
  var words = str.split(' ');
  var wordsLength = words.length;
  var ArrLength = strArr.length;
   for(var i = 0; i < ArrLength; i++){
   for(var j = 0; j < wordsLength; j++){
        if(words[j]===strArr[i])
        count.push(true);
      }
  }
  return count;
 }

document.write(keywordusage('Dive Into Python is a free book for experienced programmers', ['Python', 'python', 'scala']));}

Answer 1

您可以使用地图检查模式数组中的单词是否在字符串中：

＆＃13;

var keywordusage = (str, strArr) => strArr.map(x => str.split(" ").indexOf(x) !== -1);
console.log(keywordusage('Dive Into Python is a free book for experienced programmers', ['Python', 'python', 'scala']));

＆＃13;

Answer 2

您只需要使用array.map（）函数，该函数本质上是一个命令，允许您通过对现有数组中的每个值执行函数来创建新数组。

在这种情况下，array1已经存在，并且returnArray未定义

然后我们调用returnArray等于“通过检查textString.indexOf(array1)是否大于-1来映射array1中的每个值

.indexOf()返回字符串中字符串的位置，如果该字符串不存在，则返回-1。

function keywordusage(array1, textString) {
  var returnArray = array1.map(x => textString.indexOf(x) > -1);
  return returnArray;
}

// demonstration of usage
var checkArray = ["the", "quick", "brown"];
var checkString = "the quick red fox jumped over the lazy dog";

console.log(JSON.stringify(keywordusage(checkArray, checkString)));

Answer 3

您只需使用javascript map function。

结帐以下代码

＆＃13;

function keywordusage(str, strArr) {
  var count = [];
  strArr.map(function(s) {
    return count.push(str.indexOf(s) !== -1);
  });
  console.log(count);
  return count;
}

document.write(keywordusage('Dive Into Python is a free book for experienced programmers', ['Python', 'python', 'scala']));

＆＃13;

希望这对你有帮助。

Answer 4

function keywordusage(text, keywords) {
    var elements = text.split(" ");
    var result = Array();
    for (var i=0; i < keywords.length;i++){
        if (elements.indexOf(keywords[i]) >= 0)
            result[i] = true;
        else
            result[i] = false;
    }//end of for loop
    return result;
}

var result = keywordusage('Dive Into Python is a free book for experienced programmers', ['Python', 'python', 'scala']);
console.log(result)

通过匹配两个数组中的单词返回布尔数组

4 个答案: