How to filter all words with the letter e into an array?

Question

I am trying to put all the words that have the letter e in a separate array yet I can not figure out how to input a variable into the Regular Expression.

I have already tried plugging a variable into a metacharacter of regex.

var inputletter = "e"

startlist = ["jambee", "dangen", "oragna", "sabotta"];
filter1 = [];
var regex = new RegExp(startlist, "g");

for (var i = 0; i < startlist.length; i++) {
  if(regex.test(regex, "regex") == true) {
    filter1.push(startlist[i])

  }

};
   console.log(filter1);

Answer 1

You can use array filter function and also use includes to check if the word contains the character

 var inputletter = "e" startlist = ["jambee", "dangen", "oragna", "sabotta"]; function filter1(arr, char) { return arr.filter(function(item) { return item.includes(char) }) } console.log(filter1(startlist, inputletter)); 

Answer 2

you are using test wrong:

let regex = new RegExp("e");

...

if(regex.test(startlist[i])) {...

Answer 3

If you don't mind moving away from using a regex, you can use Javascript's array.prototype.filter() , string.prototype.toLowerCase() and the string.prototype.includes() methods to create an array where each element has at least one 'e'

 let startlist = ["jambee", "dangen", "oragna", "sabotta"]; let result = startlist.filter((element) => element.toLowerCase().includes('e')); console.log(result); 

Answer 4

If you want to keep your existing code you simply need to test the letter (the regex consisting of just that letter) against each element in the array ( startlist[i] ).

 const startlist = ['jambee', 'dangen', 'oragna', 'sabotta']; const filter1 = []; const regex = /e/; for (var i = 0; i < startlist.length; i++) { const word = startlist[i]; if (regex.test(word)) filter1.push(word); }; console.log(filter1); 

Alternatively you can use a slightly more functional method using the array filter method, and the string includes method

 const startlist = ["jambee", "dangen", "oragna", "sabotta"]; const filtered = startlist.filter(word => { return word.includes('e'); }); console.log(filtered);