Javascript：在字符串中查找单词

Question

Does Javascript have a built-in function to see if a word is present in a string? I'm not looking for something like indexOf() , but rather:

find_word('test', 'this is a test.') -> true
find_word('test', 'this is a test') -> true
find_word('test', 'I am testing this out') -> false
find_word('test', 'test this out please') -> true
find_word('test', 'attest to that if you would') -> false

Essentially, I'd like to know if my word appears, but not as part of another word. It wouldn't be too hard to implement manually, but I figured I'd ask to see if there's already a built-in function like this, since it seems like it'd be something that comes up a lot.

Answer 1

You can use split and some :

function findWord(word, str) {
  return str.split(' ').some(function(w){return w === word})
}

Or use a regex with word boundaries:

function findWord(word, str) {
  return RegExp('\\b'+ word +'\\b').test(str)
}

Answer 2

No there is not a built in function for this. You will have to add programming such as a regex or split() it by whitespace then compare the result == 'test'.

Answer 3

Moderns browsers have the Array.prototype.includes() , which determines whether an array includes a certain value among its entries, returning true or false as appropriate.

Here's an example:

 const ShoppingList = ["Milk", "Butter", "Sugar"]; console.log(`Milk ${ShoppingList.includes("Milk") ? "is" : "is not"} in the shopping list.`); console.log(`Eggs ${ShoppingList.includes("Eggs") ? "is" : "is not"} in the shopping list.`)

Answer 4

The JavaScript includes() method determines whether a string contains the characters of a specified string. This method returns true if the string contains the characters, and false if not.

Syntax:

string.includes(searchvalue, start)

Parameter values:

searchvalue    Required. The string to search for
start          Optional. Default 0. At which position to start the search

Example:

 const sentence = 'The quick brown fox jumps over the lazy dog.'; const word = 'fox'; console.log(`The word "${word}" ${sentence.includes(word) ? 'is' : 'is not'} in the sentence`);