句子代码中最长的单词不起作用

Question

Can anyone help me solve this. It does not seem to be working properly. It is supposed to find the longest word of any string of words entered into it. When I run it, it returns the first character of the string.

function LongestWord(sen) { 

  var lrg = '';

  sen.split(" ");//seperates sen into words

  for(var i = 0;i<sen.length;i++){
    var check1 = sen[i];//assigns check1 as word in sen
    if(check1.length>lrg.length){//assigns length of longest word
      lrg = check1;

       }

  }
      return lrg; 

}

// keep this function call here 
// to see how to enter arguments in JavaScript scroll down
LongestWord(readline()); 

Answer 1

The split method returns a new array. Try this:

var arr = sen.split(" ");
for(var i = 0; i < arr.length; i++) {
    var check1 = arr[i];
    if(check1.length>lrg.length) {
        lrg = check1;
    }
}

return lrg; 

Answer 2

You can also make use of regular expression for checking if a string matches or not.

var sentence = "seperates sen into words";
var splittedParts = sentence.match(/\w{1,}/gi);//You can also make use of regular //expression
for(var i = 0; i < splittedParts.length; i++) {
    var check1 = splittedParts[i];
    if(check1.length>=splittedParts.length) {
        splittedParts = check1;
    }
}
  alert(splittedParts);

Answer 3

If you match words and sort by length, longest first,

the first word in the array will be the longest.

function longestWord(str){
    return str.match(/[a-zA-Z]+/g).sort(function(a, b){
        if(a.length=== b.length) return a<b? 1: a>b? -1: 0;
        return b.length-a.length;
    })[0];
}
var s1= 'It\'s more like it is today, than it ever was before.';


longestWord(s1)

/* returned value: (String): before */

You can return an array of the same length with filter-

function longestWords(str){
    return str.match(/[a-zA-Z]+/g).sort(function(a, b){
        if(a.length=== b.length) return a<b? 1: a>b? -1: 0;
        return b.length-a.length;
    }).filter(function(w, i, A){
        return w.length=== A[0].length;
    });
}

var s1= 'It  became more like it is today, than it ever did before.';
longestWords(s1)

/* returned value: (Array): before,became */