JavaScript: String.search () cannot search for "[]" or "()"

Question

If you try to find strings such as " []" or " ()" using a function search(), this will not work.

function myFunction() {
    var str = "Visit []W3Schools!"; 
    var n = str.search("[]");
    document.getElementById("demo").innerHTML = n;
}

The search []returns -1, and the search ()returns 0. Is always.

Why is this?

+4

kaushal Apr 28 '17 at 17:26

4 answers

, . , search new RegExp.

, str.search("[]"), str.search(/[]/) ( , -1).

, str.search("()"), str.search(/()/) ( "" 0).

MDN, W3Schools.

+2

ibrahim mahrir 28 . '17 17:29

JavaScript :

"[" "(" .

:

function myFunction() {
    var str = "Visit []W3Schools!"; 
    var n = str.search("\\[]");
    document.getElementById("demo").innerHTML = n;
}

:

var n = str.search(/\[]/);

'[' . , , '' ' , unescaped' ['.

JavaScript . :

+1

BPS 28 . '17 17:34

"[]" "()" . :

str.search("\\[\\]")

, :

str.indexOf("[]")

0

Malvolio 28 . '17 17:29

ephemient · Accepted Answer · 2017-04-28T17:32:40+0000

String.search uses RegExp , and converts its argument to one, if not already. []and ()are special characters for RegExp.

:

var n = str.search(/\[\]/);

var n = str.indexOf("[]");