Hello I'm new to Javascript and I'm trying to figure out how to extract a substring from another string.
I know the substring() method captures the string from a starting index to an ending.
But in my case I want to capture a string that starts after "val=" all the way to the end of the super-string.
Ideas?
Thanks
You can either use indexOf:
var text = "something val=hello";
var result = text.substr(text.indexOf("val=") + 4);
alert(result);Or use a regex like your tags suggest:
var text = "something val=hello";
var result = /\bval=(.+)/.exec(text)[1];
alert(result);Of course, in both cases you should take care of error cases (for instance, what should happen when val= is not in the string).
var str = "val=hello world";
var idx = str.lastIndexOf('=');
var result = str.substring(idx + 1);
Your best bet would probably be to read this first: https://meta.stackexchange.com/questions/66377/what-is-the-xy-problem
Then proceed to this: How can I get query string values in JavaScript?
You can use either substr / substring:
var identifier = "val=";
var text = "your text val=foo";
var value = text.substring(text.indexOf(identifier) + identifier.length);
Or regular expression, for example using the string's method match:
var text = "your text val=foo";
var matches = text.match(/val=([\s\S]*)/);
var value = matches && matches[1];
/val=(.*)/etc.