I want to replace the text which is inside the brackets matched by regex (The first group of regex)
In other words i try to catch a string like "[SomeText][1]" and replace the number 1 with number 2 in it. The code below is replacing all the string with 2 which i dont want.
regex = new RegExp("\\[.*\\]\\[(1)\\]");
textarea.val().replace(regex, 2);
SomeText is changing. So replace("[SomeText][1]", "[SomeText][2]") does not work.
The replace method in JavaScript allows you to reference any captured match in the string (captured with parens). You reference these as $1 for the first, $2 for the second, etc. up to $9. You can change it to something like the following and I believe you'll get what you want:
regex = new RegExp("(\\[.*\\]\\[)1(\\])");
textarea.val().replace(regex, "$12$2");
If you literally always want to replace the 1 with 2, then:
var str = "[SomeText][1]";
str = str.replace(/(\[[^\]]+\])(\[1\])/g, "$1[2]");
console.log(str); // "[SomeText][2]"
Note the use of $1 to repeat the leading bit. Live Example
But the more interesting problem would be adding one to the number in the second brackets, which can be done by giving replace a function to call: Live Example
var str = "[SomeText][2]";
str = str.replace(/(\[[^\]]+\])\[(\d+)\]/g, function(m, c1, c2) {
return c1 + "[" + String(+c2 + 1) + "]";
});
console.log(str); // "[SomeText][3]"
Yep there must be some super smarty pants way to do this but here's a simple suggestion:
var bracketIdx = textarea.val().indexOf("[1]");
var value = textarea.val();
value[bracketIdx+1] = 2;
textarea.val() = value;
...sounds like you're doing something a little strange though would be happy to explain a better way if you illustrated what you want to accomplish in a little more detail. I only ask because the little snippet I wrote is a little ugly.
textarea.val().replace(/\[1\]$/, '[2]');?[1]since there is a$