string.split 由于某种原因无法正常工作

Question

I am trying to print the last name of the person "Michael" by splitting the string into an array and calling out the next word available.

When I run this code, I get undefined. I tried using Pythontutor to see what am I doing wrong and it turns out that string.split() is not working.

Can you please take a look and help figure me out what am I doing wrong?

Here is my code:

 function getMichaelLastName(inputText) { var names = inputText; var newN = [names.split(" ")]; for (var i = 0; i<newN.length; i++) { if(newN[i] == "Michael") { var Michael = newN[i++]; } return Michael; } } console.log( getMichaelLastName("Michael, how are you? - Cool, how is John Williamns and Michael Jordan? I don't know but Michael Johnson is fine. Michael do you still score points with LeBron James, Michael Green AKA Star and Michael Wood?") )

Answer 1

Your code has multiple issues:

• Don't use newN[i++] because you're updating the i value. Use newN[i+1] instead;
• You've got some scopes issues. You can learn more here: https://developer.mozilla.org/en-US/docs/Glossary/Scope
• If the last word of the sentence was 'Michael', you'll get a overflow error ( newN[i+1] does not exist).
• The split function already returns an array.

 function getMichaelLastName(inputText) { var names = inputText; var newN = names.split(" "); var michaelLastnames = [] for (var i = 0; i<newN.length - 1; i++) { if(newN[i] == "Michael") { michaelLastnames.push(newN[i+1]); } } return michaelLastnames; } var michaelLastname = getMichaelLastName("Michael, how are you? - Cool, how is John Williamns and Michael Jordan? I don't know but Michael Johnson is fine. Michael do you still score points with LeBron James, Michael Green AKA Star and Michael Wood?") console.log(michaelLastname)

Answer 2

return words after Michael

function getMichaelLastName(inputText) {
  let newArr = []
  var names = inputText;
  var newN = names.split(" "); 
  for (var i = 0; i<newN.length; i++) {
    if(newN[i] === "Michael") {
      newArr = [...newArr, newN[i + 1]]
    }
  }
  return newArr
}

if you want return last name:

function getMichaelLastName(inputText) {
  let newArr = ''
  var names = inputText;
  var newN = names.split(" "); 
  for (var i = 0; i<newN.length; i++) {
    if(newN[i] === "Michael") {
      newArr = newN[i + 1]
    }
  }
  return newArr
}

Answer 3

Regular Expression. Search for word boundaries and Michael followed by Alphabetic word.

interactive RegEx demo with explanations here: https://regex101.com/r/gC8tsi/2
/\bMichael ([AZ][az]*?)\b/g is a regular expression literal (syntax is enclosed by / to indicate a regular expression). Regular expressions are a pattern syntax designed for processing text with patterns.
\b looks for word boundaries. Basically boundaries where it finds non-word elements.
Michael_ just looks for that string.
[AZ] looks for a uppercase letter
[az]*? is a lazy sequence of lowercase letters (matches until the next word boundary \b )

The map and slice at the end is just to slice off the first name from all found names.
||[] just returns an empty array for the case where no matches are found.

 function getMichaelLastName(inputText) { return (inputText.match(/\bMichael ([AZ][az]*?)\b/g)||[]).map(x=>x.slice('Michael '.length)) } console.log( getMichaelLastName("Michael, how are you? - Cool, how is John Williamns and Michael Jordan? I don't know but Michael Johnson is fine. Michael do you still score points with LeBron James, Michael Green AKA Star and Michael Wood?") ) function getLastNames(inputText, name='Michael') { const rex = new RegExp(String.raw`\b${name} ([AZ][az]*?)\b`,'g') return (inputText.match(rex)||[]).map(x=>x.slice(name.length+1)) } console.log( getLastNames("Michael, how are you? - Cool, how is John Williamns and Michael Jordan? I don't know but Michael Johnson is fine. Michael do you still score points with LeBron James, Michael Green AKA Star and Michael Wood?",'John'), getLastNames("Michael, how are you? - Cool, how is John Williamns and Michael Jordan? I don't know but Michael Johnson is fine. Michael do you still score points with LeBron James, Michael Green AKA Star and Michael Wood?",'Michael') )

Answer 4

This code uses regex and capture the word (ie, potential lastname) after Michael<space>

const regex = /Michael (\w+)/gm;
const str = "Michael, how are you? - Cool, how is John Williamns and Michael Jordan? I don't know but Michael Johnson is fine. Michael do you still score points with LeBron James, Michael Green AKA Star and Michael Wood?";
let m;

while ((m = regex.exec(str)) !== null) {
    // This is necessary to avoid infinite loops with zero-width matches
    if (m.index === regex.lastIndex) {
        regex.lastIndex++;
    }

    // The result can be accessed through the `m`-variable.
    m.forEach((match, groupIndex) => {
        console.log(`Found match, group ${groupIndex}: ${match}`);
    });
}

Answer 5

 function getMichaelLastName(inputText) { var Michaels = []; var names = inputText; var newN = names.split(' '); for (var i = 0; i < newN.length; i++) { const x = newN[i]; if (x.includes( "Michael")) { if(newN[i+1].length>3) Michaels.push(newN[i + 1].replace('?','')); } } return Michaels; } console.log( getMichaelLastName("Michael, how are you? - Cool, how is John Williamns and Michael Jordan? I don't know but Michael Johnson is fine. Michael do you still score points with LeBron James, Michael Green AKA Star and Michael Wood?") )