Question

我正在研究一些代码，这些代码将搜索字符串并返回缺少的字母表中的任何字母。这就是我所拥有的：

function findWhatsMissing(s){
    var a = "abcdefghijklmnopqrstuvwxyz";
    //remove special characters
    s.replace(/[^a-zA-Z]/g, "");
    s = s.toLowerCase();
    //array to hold search results
    var hits = [];

    //loop through each letter in string
    for (var i = 0; i < a.length; i++) {
        var j = 0;
        //if no matches are found, push to array
        if (a[i] !== s[j]) {
                hits.push(a[i]);
        }
        else {
            j++;
        }
    }
    //log array to console
    console.log(hits);
}

但是使用测试用例： findWhatsMissing（“d a b c”）;

将d添加到缺失数组之前的所有字母中的结果。

非常感谢任何帮助。

Answer 1

在循环中，您可以使用indexOf()查看输入中是否存在该字母。像这样的东西会起作用：

for (var i = 0; i < a.length; i++) {
    if(s.indexOf(a[i]) == -1) { hits.push(a[i]); }
}

希望有所帮助！你可以看到它在这个JS小提琴中工作：https://jsfiddle.net/573jatx1/1/

Answer 2

Adam Konieska说。这样的事情会起作用：

   function findWhatsMissing(s) {
        var a = "abcdefghijklmnopqrstuvwxyz";
        s = s.toLowerCase();
        var hits = [];
        for (var i = 0; i < a.length; i++) {
            if(s.indexOf(a[i]) == -1) { hits.push(a[i]); }
        }

       console.log(hits);
    }

    findWhatsMissing("d a b c");

Answer 3

可以使用Array.prototype.filter()并在每个循环中使用indexOf()

检查字符串

function findWhatsMissing(s){
    var a = "abcdefghijklmnopqrstuvwxyz";
    //remove special characters
    s = s.replace(/[^a-zA-Z]/g, "");
    s = s.toLowerCase();
    return a.split('').filter(function(letter){
      return s.indexOf(letter) === -1;
    });
}

alert( findWhatsMissing('d f v'))

Answer 4

您可以使用indexOf：

function findWhatsMissing(s){
    var a = "abcdefghijklmnopqrstuvwxyz";
    //remove special characters
    s = s.replace(/[^a-zA-Z]/g, "");
    s = s.toLowerCase();
    //array to hold search results
    var hits = [];

    //loop through each letter in string
    for (var i = 0; i < a.length; i++) {
        //if no matches are found, push to array
        if (s.indexOf(a[i]) == -1) {
                hits.push(a[i]);
        }
    }
    //log array to console
    return hits;
}
alert(JSON.stringify(findWhatsMissing(' d a b c ')));

或两个for循环：

function findWhatsMissing(s){
  var a = "abcdefghijklmnopqrstuvwxyz";
  //remove special characters
  s = s.replace(/[^a-zA-Z]/g, "");
  s = s.toLowerCase();
  //array to hold search results
  var hits = [];

  //loop through each letter in string
  for (var i = 0; i < a.length; i++) {
    //if no matches are found, push to array
    var found = false;
    for (var j = 0; j < s.length; j++) {
      if (s[j] == a[i]) {
        found = true;
        break;
      }
    }
    if (!found) {
      hits.push(a[i]);
    }
  }
  //log array to console
  return hits;
}
alert(JSON.stringify(findWhatsMissing(' d a b c ')));

在javascript中搜索字符串中缺少字母表的字母

4 个答案: