I am trying to replace the last number of each match in between parenthesis.
so if I had cos(3 * 3)
before this regex
result = result.replace(/\d+(?:\.\d+)?/g, x => `${x}deg`)
would turn cos(3 * 3) into cos(3deg * 3deg)
I need only the last number to be changed to deg
So if I had cos(3 * 3) + cos(3 * 2) it would be cos(3 * 3deg) + cos(3 * 2deg)
What regular expression magic could I use to do this.
... /\((?<first>.*?)(?<last>[\d.]+)\)/g ...
// see ... [https://regex101.com/r/aDXe3B/1]
const regXLastNumberWithinParentheses =
/\((?<first>.*?)(?<last>[\d.]+)\)/g;
const sampleData =
`cos(3 * 3) + cos(3 * 24.5), cos(2 * 3) + cos(3 * 2.4)
cos(3 * 3.4) + cos(3 * 45), cos(4 * 2) + cos(3 * 245)`;
console.log(
sampleData.replace(
regXLastNumberWithinParentheses,
(match, first, last) => `(${ first }${ last }deg)`
)
);.as-console-wrapper { min-height: 100%!important; top: 0; }1st Edit
Any idea why in this (3*(2+1+1)-12/5) is coming out as (3*(2+1+1deg)-12/5) it needs to match the last number regardless so it would be (3 *(2+1+1deg) - 23/5deg) – Nik Hendricks
@NikHendricks ... "Any idea why ...?" Yes of cause. Though the above regex matches anything and a final number in between parentheses, it does so just for un-nested parentheses (any nested structures can not be recognized). ... Question: Could one assume that the passed string does always feature validly nested parentheses? If yes, it leads to more straightforward regex replacement patterns because a regex then does not need to also validate the parentheses syntax. – Peter Seliger
... regex update ... /(?<![.\d])(?<number>\d*(?:\.\d+)?)\s*\)/g
// see ... [https://regex101.com/r/aDXe3B/2]
const regXLastNumberBeforeClosingParenthesis =
/(?<![.\d])(?<number>\d*(?:\.\d+)?)\s*\)/g;
const sampleData =
`cos(3 * 3) + cos(3 * 24.5 ), cos(2 * 3 ) + cos(3 * 2.4)
cos(3 * 3.4) + cos(3 * 45 ), cos(4 * 2 ) + cos(3 * 245)
(3 * (2 + 1 + 1) - 23/5)`;
console.log(
sampleData.replace(
regXLastNumberBeforeClosingParenthesis,
(match, number) => `${ number }deg)`
)
);.as-console-wrapper { min-height: 100%!important; top: 0; }2nd Edit
for me the desired result for 3*(1571-sin(1 * 12)) would be 3*(1571deg -sin(1 * 12deg)) the last or only occurrence of a number is replaced with xdeg – Nik Hendricks
... regex update ... /(?<number>(?<!\.)\d+(?:\.\d+)?|(?<![\d.])(?:\.\d+)(?!\.))(?<termination>\s*[-+)])/g
// see ... [https://regex101.com/r/aDXe3B/3]
const regXValidNumberBeforePlusOrMinusOrClosingParenthesis =
/(?<number>(?<!\.)\d+(?:\.\d+)?|(?<![\d.])(?:\.\d+)(?!\.))(?<termination>\s*[-+)])/g;
const sampleData =
`cos(3 * 3) + cos(3 * 24.5 ), cos(2 * 3 ) + cos(3 * .2.4)
cos(3 * 3.4) + cos(3 * 45 ), cos(4 * .24) + cos(3 * 245 )
(3 *(2 + 1 + 1) - 23/5 )
3 * (1571 - sin(12))`;
console.log(
sampleData.replace(
regXValidNumberBeforePlusOrMinusOrClosingParenthesis, '$1deg$2'
)
);.as-console-wrapper { min-height: 100%!important; top: 0; }Regarding the last iteration/edit ... in case number validation is not important (because the input is trusted), one of cause could achieve the same result with a less strict, thus simpler, regex which does not exclusively match valid numbers ... /(?<dotsAndDigits>[.\d]+)(?<termination>\s*[-+)])/g.
(3*(2+1+1)-12/5) is coming out as (3*(2+1+1deg)-12/5) it needs to match the last number regardless so it would be (3 *(2+1+1deg) - 23/5deg)
You can simply use the closing braces to replace like this:
var result = "cos(3 * 3) + cos(3 * 245)"
result = result.replace(/(\d+)(\))/g,'$1deg)')
console.log(result)Or just replace the last bracket.
var result = "cos(3 * 90) + sin(3 * 2)"
result = result.replace(/\)/g,'deg)')
console.log(result)With Decimal add a character class using
[]for.and digits
var result = "cos(3 * 3.4) + cos(3 * 245.5)"
result = result.replace(/([\d\.]+)(\))/g,'$1deg)')
console.log(result)Any equation at the last number
var result = "3*(1571-sin(12))"
result = result.replace(/(\d\s{0,}\*+\d{0,})(.*\))/g,'$1$2deg')
console.log(result)
xdeg or just 1deg
xdeg will work). Its amazing how just calming down and rethinking the whole thing can show there are much easier more logical options. Thank you.The insertion position for deg is just a place between two defined Assertions.
(?<=\([^()]*\d)(?=[^()\d]*\))
https://regex101.com/r/sjw3CX/1
(?<= \( [^()]* \d ) # Lookbehind open parenth up to last number
(?= [^()\d]* \) ) # Lookahead no digits and must have a closing parenth
var input = " cos(3 * 3) + cos(3 * 2)"
var output = input.replace(/(?<=\([^()]*\d)(?=[^()\d]*\))/g,'deg')
console.log(output)
\d+(?=\s?\))This will match any numeral before closing brackets.