const regex = /(?(DEFINE)
(?<decimal>(?(int)([.][0-9]+)?|[.][0-9]+))
(?<percentage>
(100|
(?<int>([0-9]|[1-9][0-9]))? # Have integer be optional (0-100 only)
(?P>decimal) # Have decimal required when an integer is not included
)
(?<symbol>%)
)
(?<hue>
(?<int>36[0]|3[0-5][0-9]|[12][0-9][0-9]|[1-9]?[0-9])? # Have integer be optional
(?P>decimal) # Have decimal required when an integer is not included
(?<symbol>\s*deg\s*)?
)
(?<alpha>
(?(alpha),\s*(
1[.]0|
(?<int>0)? # Have integer be optional
(?P>decimal) # Have decimal required when integer is not incldue
)\s*)
)
(?<hsl>\s*(?P>hue)\s*,\s*(?P>percentage)\s*,\s*(?P>percentage)\s*)
)
hsl(?<alpha>a)?\((?P>hsl)(?P>alpha)\)/gi;
// Alternative syntax using RegExp constructor
// const regex = new RegExp('(?(DEFINE)
(?<decimal>(?(int)([.][0-9]+)?|[.][0-9]+))
(?<percentage>
(100|
(?<int>([0-9]|[1-9][0-9]))? # Have integer be optional (0-100 only)
(?P>decimal) # Have decimal required when an integer is not included
)
(?<symbol>%)
)
(?<hue>
(?<int>36[0]|3[0-5][0-9]|[12][0-9][0-9]|[1-9]?[0-9])? # Have integer be optional
(?P>decimal) # Have decimal required when an integer is not included
(?<symbol>\\s*deg\\s*)?
)
(?<alpha>
(?(alpha),\\s*(
1[.]0|
(?<int>0)? # Have integer be optional
(?P>decimal) # Have decimal required when integer is not incldue
)\\s*)
)
(?<hsl>\\s*(?P>hue)\\s*,\\s*(?P>percentage)\\s*,\\s*(?P>percentage)\\s*)
)
hsl(?<alpha>a)?\\((?P>hsl)(?P>alpha)\\)', 'gi')
const str = `hsl(10, 50deg, 150%)
HSLA(50.35, .531, 10%)
HSLA(50.5deg, .531%, .9%, 1.0)`;
// Reset `lastIndex` if this regex is defined globally
// regex.lastIndex = 0;
let m;
while ((m = regex.exec(str)) !== null) {
// This is necessary to avoid infinite loops with zero-width matches
if (m.index === regex.lastIndex) {
regex.lastIndex++;
}
// The result can be accessed through the `m`-variable.
m.forEach((match, groupIndex) => {
console.log(`Found match, group ${groupIndex}: ${match}`);
});
}
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for JavaScript, please visit: https://developer.mozilla.org/en/docs/Web/JavaScript/Guide/Regular_Expressions