const regex = /^\.?\d{1,5}(?:\.\d{1,5})*$/gm;
// Alternative syntax using RegExp constructor
// const regex = new RegExp('^\\.?\\d{1,5}(?:\\.\\d{1,5})*$', 'gm')
const str = `1
12
123
1234
12345
123456
1.2
.1
.1.2
1234567890
1234567890.
12345.67890
.1234567890
123.4567.890
.1234567890.
12345..67890
.1234.567890.
1.234.567.890
.123.456.7890
.1.2.3.4.5.6.7.8.9.0
.1.2.3.4.5.6.7.8.9.0.`;
// 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