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replace words that starts with "(uuid: )"

I would like to replace text using javascript/regex
"TV "my-samsung" (UUID: a1c3bbc1d27c5be8:8baabe2fa7f5d9ca) is already switched off."
with
TV 'my-samsung' is already switched off.
by removing text (UUID: ) and replace " with '
Looks like regex can be used
\([\s\S]*?\)
https://regex101.com/r/xXDncn/1
or have also tried using replace method in JS
str = str.replace("(UUID", "");

You can use
const str = '" "Tv "my-samsung" (UUID: a1c3bbc1d27c5be8:8baabe2fa7f5d9ca) is already switched-off""';
console.log(
str.replace(/\s*\(UUID:[^()]*\)/g, '').replace(/^[\s"]+|[\s"]+$/g, '').replaceAll('"', "'")
)
See the first regex demo. It matches
\s* - zero or more whitespaces
\(UUID: - (UUID: string
[^()]* - zero or more chars other than ( and )
\) - a ) char.
The g flag makes it replace all occurrences.
The second regex removes trailing and leading whitespace and double quotation marks:
^[\s"]+ - one or more whitespaces and double quotes at the start of string
| - or
[\s"]+$ - one or more whitespaces and double quotes at the end of string.
The .replaceAll('"', "'") is necessary to replace all " with ' chars.
It is not a good idea to merge these two operations into one as the replacements are different. Here is how it could be done, just for learning purposes:
const str = '" "Tv "my-samsung" (UUID: a1c3bbc1d27c5be8:8baabe2fa7f5d9ca) is already switched-off""';
console.log(
str.replace(/^[\s"]+|[\s"]+$|\s*\(UUID:[^()]*\)|(")/g, (x,y) => y ? "'" : "")
)
That is, " is captured into Group 1, the replacement is now a callable, where x is the whole match and y is the Group 1 contents. If Group 1 matched, the replacement is ', else, the replacement is an empty string (to remove the match found).

you can try this
str.replace(/\(.*?\)/, "")
str.replace(/\(.*?\)/, "with")
--- update ---
const str = `"TV "my-samsung" (UUID: a1c3bbc1d27c5be8:8baabe2fa7f5d9ca) is already switched off."`;
const a = str.replace(/"(.*?)\(.*\)(.*)"/, (a, b, c) => {
return b.replace(/"/g, "'") + c
});
console.log(a); //TV 'my-samsung' is already switched off.

Check if first and last character contains given special char

I have input string
..-----''''''.......VAibhavs.sharma'..'-.'-.''-....''
I want to check if the first and last char place contains - or ' or ..
If yes then trim until we get name.
Expected output : VAibhavs.sharma
I am using like this.
while (
myString.charAt(0) == "." ||
myString.charAt(0) == "'" ||
myString.charAt(0) == "-" ||
myString.charAt(myString.length - 1) == "." ||
myString.charAt(myString.length - 1) == "'" ||
myString.charAt(myString.length - 1) == "-"
)
I know this is not correct way. How can I use regex?
I tried /^\'$. But this only checks or first char for a single special char.

You can use regular expression:
input = "..-----''''''.......VAibhavs.sharma'..'-.'-.''-....''"
output = input.replace(/^[-'\.]+/,"").replace(/[-'\.]+$/,"")
console.log(output)
[-'\.] ... -, ' or . character
+ ... one or more times
^ ... beginning of the string
$ ... end of the string
EDIT:
using match:
input = "..-----''''''.......VAibhavs.sharma'..'-.'-.''-....''"
output = input.match(/^[-'\.]+(.*?)[-'\.]+$/)[1]
console.log(output)
(...) ... (1st) group
.*? ... any chacter, zero or more times, ? means non-greedy
.match(...)[1] ... 1 means 1st group

There is already one accepted answer but still, this is how I would do.
var pattern = /\b[A-Za-z.]+\b/gm;
var str = "..-----''''''.......VAibhavs.sharma'..'-.'-.''-....''";
console.log(str.match(pattern));
// Output
// ["VAibhavs.sharma"]
\b is a zero-width word boundary. It matches positions where one side is a word character (usually a letter, digit or underscore) and the other side is not a word character (for instance, it may be the beginning of the string or a space character).

regular expression to check only one decimal point

I have following regular expression to check only one decimal point for type number tag in html
^-?[0-9]*\\.?[0-9]*$
but this regular failed to check If I put decimal at the end e.g 12.12.
what further I have to add to check this

I think your regex can be easily fixed using a + instead of last * quantifier:
^-?[0-9]*\.?[0-9]+$
Tests:
const regex = /^-?[0-9]*\.?[0-9]+$/gm;
console.log('regex.test?')
console.log('12 = ' + regex.test('12'));
console.log('12. = ' + regex.test('12.'));
console.log('12.1 = ' + regex.test('12.1'));
console.log('12.12. = ' + regex.test('12.12.'));
console.log('-1 = ' + regex.test('-1'));
console.log('-1. = ' + regex.test('-1.'));
console.log('-1.2 = ' + regex.test('-1.2'));
console.log('-.12 = ' + regex.test('-.12'));
console.log('-. = ' + regex.test('-.'));
console.log('-. = ' + regex.test('-'));
console.log('. = ' + regex.test('.'));
Demo

Can you try the below : [1-9]\d*(\.\d+)?$

The simplest way to allow a possible . at the end is to have \.? just before the $. Also, the double \ looks wrong (unless you need it for escaping a \ in the context in which you are using it):
^-?[0-9]*\.?[0-9]*\.?$
But please recognize that your regex does not require any actual digits, so will match some non-numbers, like ., -. and (with my edit) -.. The above regex will also match an empty string!
You will want to either change your regex to require digits, or take into account somewhere else that they might not be there.

What does "(\'' + element + '\')" mean?

function expand(element) {
var target = document.getElementById(element);
var h = target.offsetHeight;
var sh = target.scrollHeight;
var loopTimer = setTimeout('expand(\'' + element + '\')', 10);
if (h < sh) {
h += 1;
} else {
clearTimeout(loopTimer);
alert("伸縮完成");
}
target.style.height = h + "px"
}

\' is an escape character for ', so what this is doing is building a string that can be consumed as a function, which contains a parameter, which is wrapped in single quotes...
'expand(\''
The above portion "opens" the string, applies expand( as a literal, then an escaped ', followed by one more ' to close that portion of the string. So, the return on that is:
expand('
Next, they concatenate the value of element variable:
'expand(\'' + element
The string now contains:
expand('elementVariableValue
Next up is to open another literal string, add in another single quote (escaped), followed by the closing parenthese:
'\')'
this is evaluated to:
')
put it all together and you get:
expand('elementVariableValue')
(which is finally interpreted as a function for the timeout).
Now, with JavaScript, you can use both " and ' for string delimiters, so much easier might have been:
setTimeout("expand('" + element + "')", 10);

Code in your example is a recursive call. It's a timer and the callback is expand(element). Understand this, you can easy understand that var loopTimer = setTimeout('expand(\'' + element + '\')', 10); means another call to expand(element). However, function expand need a string parameter, so \'' + element + '\' it is. Finally, if element here equals to scaleid, we finally get expand('scaleid'), it is obviously another call to expand(). Cause it is in string, so \' is needed to escape it.

In Javascript you can pass as the first parameter of the function a string, this string is evaluated as if you use eval(). That code is like if you call the function expand("something") every 10 milliseconds.

Check for existence of a keyword within a code string

I’m loading the contents of a JS file using FileReader and dumping the results into a textarea container. I then want to run some checks on the actual JS file.
I know there are probably tools out there for this already (or better ways), but this is for a closed-environment project.
After the textarea contains the content of the JS file as one large string, I need to loop the string and find all instances of parseInt() to check if they have been supplied with a radix.
I would provide code, but I have nothing working at this point. Any ideas?

The following snippet will search the string value of your <textarea> element for parseInt() and output the occurences, with radix where applicable:
var textareaValue = 'var func = function(){' +
'var i = parseInt(1,1);' +
'var j = parseInt(10, 10);' +
'var k = parseInt(3) + j;' +
'};';
occurences = textareaValue.match(/parseInt\(.+?(, ?\d+)?\)/g);
occurences.forEach(function(occurence){
var hasRadix = /, ?\d+\)$/.test(occurence);
document.body.innerHTML += '<p>"' + occurence + '" has ' +
(hasRadix ? 'a' : 'no') + ' radix' +
(hasRadix ? ' (' + occurence.match(/, ?(\d+)\)$/)[1] + ')' : '') +
'.</p>';
});
Note that this is no actual syntax interpretation, it’s merely text analysis. You will have to go from the result, which comprises all the occurences of parseInt() as strings. Also, JavaScript allows whitespace, comments, expressions and other witchcraft at the text passage in question. You might to have to check for anything.
The actual regex /parseInt\(.+?(, ?\d+)?\)/g will demand…
parseInt( at the beginning of the match
any characters (might need to be expanded to include brackets, etc. by :punct:)
as optional group, determining whether a radix is supplied or not:
a comma, an optional space (might need to respond to any number of whitespace using *)
at least one digit (might need to limit to {1,2}, because only 2 to 36 are valid)
a trailing closing bracket.

The following function should be able to tell the difference between usages of parseInt with radix versus its usages without radix by simplistic regex matching:
function have_radix(str){
parseIntRegex = /parseInt\(.+?\)/g;
parseIntRegexWithRadix = /parseInt\(.+?(,.+?\))/g;
indices = [];
while ( (result = parseIntRegex.exec(str)) ) {
indices.push(result.index);
}
count = indices.length;
indices = [];
while ( (result = parseIntRegexWithRadix.exec(str)) ) {
indices.push(result.index);
}
diff = count - indices.length;
return diff;
}