CODEWITHSUNDEEP
javascriptstring
chriz
chriz

Reputation: 1345

check substrings in a string in java script

i want to check particular character occurrence in a string java script,
following is what i need

i tried this

if(text .indexOf('()') === -1)
{
  alert("not function");
}

but how i can check whether brackets are in very end.

Upvotes: 0

Views: 174

Answers (7)

MT0
MT0

Reputation: 168730

The regular expression ^\w+\.\w+$ will match a string consisting of:

  • the start of the string;
  • a sequence of "word" characters;
  • followed by a full stop;
  • then another sequence of "word" characters; and
  • finally, the end of the string.

Similarly, the regular expression ^\w+\(\)$ will match a string consisting of:

  • the start of a string;
  • a sequence of "word" characters;
  • followed by open and closing round brackets; and
  • finally, the end of the string.

You can wrap it in a function like this:

function check( text_to_match ){
    if(text_to_match.match(/^\w+\.\w+/)) 
        console.log("it is an object ");
    else if(text_to_match.match(/^\w+\(\)$/)) 
        console.log("it is an function");
}

Upvotes: 1

HighBoots
HighBoots

Reputation: 293

You an use RegEx:

var one = "ABC.DEF";
var two = "ABC()";
var three = "()blank";

function check(string){

  // Matches: ABC.DEF  and Does not match: ABC. or .DEF
  if(/\w+\.\w+/.test(string)) 
    console.log("it is a function");

  // \(\) interpreted as (). Matches : ABC() ; Does not match: ()ABC or ABC()ABC
  else if(/\w+\(\)$/.test(string)) 
    console.log("it's an object");

  // Not found
  else
    console.log("something else")

}

check(one);    // it is a function
check(two);    // it's an object
check(three);  // something else

The $ checks if the match(()) is at the end of the line.
The \w+ is count one or more occurrences of "A-Za-z0-9_".

JSBin

Upvotes: 3

Paul S.
Paul S.

Reputation: 66404

String.prototype.slice lets you use negative numbers to tackle the other end of the String.

'foobar'.slice(-2); // "ar"

so

if (text.slice(-2) === '()') {
    // last two digits were "()"
}

Upvotes: 0

Kris Krause
Kris Krause

Reputation: 7326

http://jsfiddle.net/h9V2z/2/

String.prototype.endsWith = function(suffix) {
   return this.indexOf(suffix, this.length - suffix.length) !== -1;
};

if("ABC()".indexOf("()") > -1) {
    alert("it is a function");
}

if("ABC.DEF".indexOf(".") > -1) {
    alert("it is an object");
}

if("ABC()".endsWith("()")=== true) {
    alert("ends with ()");
}

if("ABC()".endsWith("()whatever")=== true) {
    alert("ends with ()");
}

Upvotes: 1

Anoop Joshi P
Anoop Joshi P

Reputation: 25537

try

 var a = "abc()";
        if (a[a.length-1] == ')' && a[a.length - 2] == '(') {
            alert("function");
        }

Upvotes: 1

Rajiv007
Rajiv007

Reputation: 1136

Try this:

  if(text.substring(2) == "()")
  {
    alert("it is function");
  }

Upvotes: 0

Clément Andraud
Clément Andraud

Reputation: 9279

indexOf returns the position of the string in the other string. If not found, it will return -1:

var s = "foo";
alert(s.indexOf("oo") != -1);

Upvotes: 0

Related Questions