Numbers

Scientific Notation

Matches numbers in scientific/exponential notation (e.g., 1.5e10).

Available in

JavaScript / ECMAScript code

jsJavaScript

const re = new RegExp("^-?\\d+(\\.\\d+)?[eE][+-]?\\d+$", "");
const input = "1.5e10";
const matches = [...input.matchAll(re)];
console.log(matches.map(m => m[0]));

Uses `String.prototype.matchAll` for global iteration (Node 12+ / all modern browsers).

Python (re) code

pyPython

import re

pattern = re.compile(r"^-?\d+(\.\d+)?[eE][+-]?\d+$")
input_text = "1.5e10"
for m in pattern.finditer(input_text):
    print(m.group(0))

Stdlib `re` module — no third-party dependency. Works on Python 3.6+.

Go (RE2) code

goGo

package main

import (
	"fmt"
	"regexp"
)

func main() {
	re := regexp.MustCompile(`^-?\d+(\.\d+)?[eE][+-]?\d+$`)
	input := `1.5e10`
	for _, match := range re.FindAllString(input, -1) {
		fmt.Println(match)
	}
}

Uses `regexp.MustCompile` (panics on bad patterns at startup) and `FindAllString` for all matches.