JavaScript or jQuery equivalent of PHP's strstr() function

Question

Is there a function in jQuery or JavaScript that does the same as strstr() in PHP?

I have an AJAX response that should be 1,2,3,12,13,23 or 123. I want to check if 1 exists, then if 2 exists then if 3 exists.

Answer 1

Ok I just found something that works!

http://my-sliit.blogspot.com/2008/06/search-string-javascript-like-strstr-in.html

Thanks for your contributions :)

Answer 2

Try using this:

function strstr(haystack, needle, bool) {
    // Finds first occurrence of a string within another
    //
    // version: 1103.1210
    // discuss at: http://phpjs.org/functions/strstr    // +   original by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
    // +   bugfixed by: Onno Marsman
    // +   improved by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
    // *     example 1: strstr(‘Kevin van Zonneveld’, ‘van’);
    // *     returns 1: ‘van Zonneveld’    // *     example 2: strstr(‘Kevin van Zonneveld’, ‘van’, true);
    // *     returns 2: ‘Kevin ‘
    // *     example 3: strstr(‘name@example.com’, ‘@’);
    // *     returns 3: ‘@example.com’
    // *     example 4: strstr(‘name@example.com’, ‘@’, true);    // *     returns 4: ‘name’
    var pos = 0;

    haystack += "";
    pos = haystack.indexOf(needle); if (pos == -1) {
        return false;
    } else {
        if (bool) {
            return haystack.substr(0, pos);
        } else {
            return haystack.slice(pos);
        }
    }
}

(From http://phpjs.org/functions/strstr:551)

Overall phpjs is pretty phenomenal.

Answer 3

Read about these javascript functions - indexOF() and lastIndexOf().

Answer 4

Well, not built in. String.indexOf( String str ) returns the integer index of the substring but then, you can easily build one: http://aimtb.wordpress.com/2011/03/16/strstr-in-javascript/

function strstr(haystack, needle, bool) {
    // Finds first occurrence of a string within another
    //
    // version: 1103.1210
    // discuss at: http://phpjs.org/functions/strstr    // +   original by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
    // +   bugfixed by: Onno Marsman
    // +   improved by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
    // *     example 1: strstr(‘Kevin van Zonneveld’, ‘van’);
    // *     returns 1: ‘van Zonneveld’    // *     example 2: strstr(‘Kevin van Zonneveld’, ‘van’, true);
    // *     returns 2: ‘Kevin ‘
    // *     example 3: strstr(‘name@example.com’, ‘@’);
    // *     returns 3: ‘@example.com’
    // *     example 4: strstr(‘name@example.com’, ‘@’, true);    // *     returns 4: ‘name’
    var pos = 0;

    haystack += "";
    pos = haystack.indexOf(needle); if (pos == -1) {
        return false;
    } else {
        if (bool) {
            return haystack.substr(0, pos);
        } else {
            return haystack.slice(pos);
        }
    }
}

Answer 5

Here is an implementation without any library/method calls:

function strstr (haystack, needle) {
    var i = 0,
        tempLength = 0,
        temp = [];
    for (;;) {
        if (haystack[i] === undefined || needle == null) {
            return "No match";
        }
        //if the char doesn't match then reset
        else if (haystack[i] !== needle[tempLength]) {
            temp = [];
            tempLength = 0;
        } 
        //the char matches so let's store it.
        else if (haystack[i] === needle[tempLength]) {
            temp[tempLength] = haystack[i];
            if (needle[tempLength + 1] === undefined) {
                return temp;
            }
            tempLength++;
        }
     i++;
   }
};

Answer 6

 const isSame = function(indx, haystack, needle){
    let j = 0;
    for(let i=indx, len = indx + needle.length; i< len; i++) {
       if (haystack[i] !== needle[j++]){
          return false;      
       }
    }
    return true;
}

var strStr = function(haystack, needle) {
    if (!needle) {
        return 0;
    }
        
    for(let i=0; i<haystack.length; i++) {
        if (haystack[i] === needle[0]){
           if(isSame(i, haystack, needle)){
               return i;
           };
        }
    }
    return -1;
};
console.log(strStr("hello", "ll"));
console.log(strStr("mississippi", "issip"));

Base conditions:- when needle is empty string, it will return 0. If there is no match found it will return -1.