Understanding how to count the characters in a string in order to use slice() on a part of the strin-CodePudding

I am learning JavaScript , the fundamentals for now and what I don’t get, is how to count the characters in the string in order to use the slice on the certain string and extract a certain word out of the string. For example

let text = “JavaScript”, “apples”, “avocado”);
let newText = text.slice(?),(?);

How do I know or count the position of apples for example or JavaScript? Thank you!

CodePudding user response：

Try like this:

let text = "JavaScript, apples, avocado";
let newText = text.slice(text.indexOf("JavaScript"));
let newText2 = text.slice(text.indexOf("apples"));
console.log(newText)
console.log(newText2)

CodePudding user response：

split the string into an array, filter out the item you don't want, and then splice in the string you do want. Finally, join the array elements into a new string.

const str = 'JavaScript, apples, avocado';

function replace(str, search, replacement) {

  // Create an array using `split`
  const arr = str.split(', ');
  
  // Find the index of the item you're looking for
  const index = arr.findIndex(el => el === search);

  // `filter` out the element you don't want
  const newArr = arr.filter(el => el !== search);

  // `splice` in the new replacement string
  newArr.splice(index, 0, replacement);

  // Return the new string
  return newArr.join(', ');
  
}

console.log(replace(str, 'apples', 'biscuit'));

CodePudding user response：

Few observations/suggestions :

String will always wrapped with the quotes but in your post it is not looks like a string.
Why you want to slice to get the word from that string ? You can convert that string into an array and then get that word.

Implementation steps :

Split string and convert that in an array using String.split() method.
Now we can find for the word you want to search from an array using Array.find() method.

Working Demo :

// Input string
const text = "JavaScript, apples, avocado";
const searchText = 'apples';

// Split string and convert that in an array using String.split() method.
const splittedStringArray = text.split(',');

// Now we can find for the word from splittedStringArray using Array.find() method.
const result = splittedStringArray.find(item => item.trim() === searchText);

// Output
console.log(result);