$a = 'how are you';
if [strpos[$a,'are'] !== false] {
echo 'true';
}
In PHP, we can use the code above to check if a string contain specific words, but how can I do the same function in JavaScript/jQuery?
j08691
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asked Mar 22, 2011 at 8:18
Charles YeungCharles Yeung
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4
you can use indexOf for this
var a = 'how are you';
if [a.indexOf['are'] > -1] {
return true;
} else {
return false;
}
Edit: This is an old answer that keeps getting up votes every once in a while so I thought I should clarify that in the above code, the if clause is not required at all because the expression itself is a boolean. Here is a better version of it which you should use,
var a = 'how are you';
return a.indexOf['are'] > -1;
Update in ECMAScript2016:
var a = 'how are you';
return a.includes['are']; //true
answered Mar 22, 2011 at 8:22
3
indexOf/includes should not be used for finding whole words:
A word [in western culture] is a drawing of a symbols close to each other, with some space between each word. A word is considered as such if it's a complete piece of characters draw together and not a partial part of it:
"has a word".indexOf['wor'] // 6 ["wor" is not a word in this sentence]
"has a word".includes['ha'] // true ["ha" is not a word in this sentence]
Check if a single word [whole word] is in the string
Find a real whole word, not just if the letters of that word are somewhere in the string.
const wordInString = [s, word] => new RegExp['\\b' + word + '\\b', 'i'].test[s];
// tests
[
'', // true
' ', // true
'did', // true
'id', // flase
'yo ', // flase
'you', // true
'you not' // true
].forEach[q => console.log[
wordInString['dID You, or did you NOt, gEt WHy?', q]
]]
console.log[
wordInString['did you, or did you not, get why?', 'you'] // true
]Check if all words are in the string
var stringHasAll = [s, query] =>
// convert the query to array of "words" & checks EVERY item is contained in the string
query.split[' '].every[q => new RegExp['\\b' + q + '\\b', 'i'].test[s]];
// tests
[
'', // true
' ', // true
'aa', // true
'aa ', // true
' aa', // true
'd b', // false
'aaa', // false
'a b', // false
'a a a a a ', // false
].forEach[q => console.log[
stringHasAll['aA bB cC dD', q]
]]answered Jan 12, 2014 at 23:41
vsyncvsync
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6
If you are looking for exact words and don't want it to match things like "nightmare" [which is probably what you need], you can use a regex:
/\bare\b/gi
\b = word boundary
g = global
i = case insensitive [if needed]
If you just want to find the characters "are", then use indexOf.
If you want to match arbitrary words, you have to programatically construct a RegExp [regular expression] object itself based on the word string and use test.
answered Mar 22, 2011 at 8:27
Stephen ChungStephen Chung
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You're looking for the indexOf function:
if [str.indexOf["are"] >= 0]{//Do stuff}
answered Mar 22, 2011 at 8:22
evbaileyevbailey
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You might wanna use include method in JS.
var sentence = "This is my line";
console.log[sentence.includes["my"]];
//returns true if substring is present.
PS: includes is case sensitive.
answered Apr 16, 2018 at 7:26
An easy way to do it to use Regex match[] method :-
For Example
var str ="Hi, Its stacks over flow and stackoverflow Rocks."
// It will check word from beginning to the end of the string
if[str.match[/[^|\W]stack[$|\W]/]] {
alert['Word Match'];
}else {
alert['Word not found'];
}
Check the fiddle
NOTE: For adding case sensitiveness update the regex with /[^|\W]stack[$|\W]/i
Thanks
Vineeth Sai
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answered Sep 20, 2018 at 6:33
In javascript the includes[] method can be used to determines whether a string contains particular word [or characters at specified position]. Its case sensitive.
var str = "Hello there.";
var check1 = str.includes["there"]; //true
var check2 = str.includes["There"]; //false, the method is case sensitive
var check3 = str.includes["her"]; //true
var check4 = str.includes["o",4]; //true, o is at position 4 [start at 0]
var check5 = str.includes["o",6]; //false o is not at position 6
answered Oct 20, 2019 at 8:09
ZeniZeni
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1
This will
/\bword\b/.test["Thisword is not valid"];
return false, when this one
/\bword\b/.test["This word is valid"];
will
return true.
answered Jun 19, 2015 at 17:07
JahidJahid
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var str1 = "STACKOVERFLOW";
var str2 = "OVER";
if[str1.indexOf[str2] != -1]{
console.log[str2 + " found"];
}answered Aug 29, 2018 at 6:09
Using a conditional ternary operator
str = 'I am on StackOverflow';
str.match[/[^|\W]StackOverflow[$|\W]/] ? 'Found. Why lie?' : 'Not Found';
answered Jan 21 at 20:28
WiiLFWiiLF
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If you'd like to find a single word in a string without regular expressions, you can do as follows:
function isWordInString[needle, haystack] {
return haystack
.split[' ']
.some[p => [p === needle]];
}
isWordInString['hello', 'hello great world!']; // true
isWordInString['eat', 'hello great world!']; // false
Advantages over regex:
- Works with non-latin characters like Hebrew
- No need to sanitize the word you search in the string. Some methods in other answers will fail and return a false positive when searching for a "." [dot]
answered Jun 8 at 9:42
ArikArik
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