Javascript string equals on of these symbols

Question

I am trying to evaluate if a string is equal to one of these symbols |\~+

But this doesn't work:

var a = 'abcted',
    b = '|\~+';

if( a !== b ){
}

So if a is equal to one of the symbols in b, is evaluates to false.

Are you doing a string to string comparison, or are you trying to see if any one singular character in b is in the string a? — vandsh, Jun 08 '15 at 18:56
possible duplicate of [How can I check if one string contains another substring?](http://stackoverflow.com/questions/1789945/how-can-i-check-if-one-string-contains-another-substring) — , Jun 08 '15 at 19:05
Please clarify your specific problem or add additional details to highlight exactly what you need. As it's currently written, it’s hard to tell exactly what you're asking. — thefourtheye, Jun 08 '15 at 19:07

GolezTrol · Accepted Answer · 2015-06-08T19:10:45.653

4

You can simply check if one string contains another using the method indexOf:

var b = '|\~+';
if (b.indexOf(a) == -1) {
  // b doesn't contain a
}

A new suggestion is made for the function includes, which would work like this, but not (yet) in many browsers.

var b = '|\~+';
if (!b.includes(a)) {
  // b doesn't contain a
}

edited Jun 08 '15 at 19:10

answered Jun 08 '15 at 18:55

GolezTrol

114,394
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This will work only if the entire string `a` is in `b`. If `a` is a substring of `b` – thefourtheye Jun 08 '15 at 19:02
That is what was asked: *".. if a string is equal to one of these symbols"* – GolezTrol Jun 08 '15 at 19:03
Its not very clear what OP is trying to do. If we look at the example, `a` is not a single character string. – thefourtheye Jun 08 '15 at 19:08

thefourtheye · Answer 2 · 2015-06-08T19:06:00.593

You can use Regular Expression to solve this, like this

if (/[|\\~\+]/.test(a) === false) {
    // `a` doesn't contain any of the symbols.
}

[|\\~\+] checks if any of the characters in the character group is in a. If none of them are there then test will return false.

console.log(/[|\\~\+]/.test("abcted"));
// false
console.log(/[|\\~\+]/.test("abc|ted"));
// true
console.log(/[|\\~\+]/.test("abc\\ted"));
// true
console.log(/[|\\~\+]/.test("abc~ted"));
// true
console.log(/[|\\~\+]/.test("abc+ted"));
// true

score 1 · Answer 3 · answered Jun 08 '15 at 19:01

1

I prefer to use RegEx where possible, but for those who are not wanting to:

var a = 'abcted',
    b = '|\~+';

for (var i = 0, len = b.length; i < len; i++) {
    if (a.indexOf(b[i]))  
    {   
        alert(b[i]);
    }
}

answered Jun 08 '15 at 19:01

vandsh

1,329
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Javascript string equals on of these symbols

3 Answers3