1 Number: ^[0-9]*$
2 N-bit number: ^\d{n}$
3 Number of at least n digits: ^\d{n,}$
4 m-n digits: ^\d{m,n}$
Numbers starting with 50 and non 0: ^ (0|[ 1-9][0-9]*) $
6 numbers with a maximum of two decimal places starting with non 0: ^ ([1-9][0-9]*) + (. [ 0-9]{1,2})? $
7 positive or negative numbers with 1-2 decimal places: ^ (-)? \d+ (. \d{1,2})? $
8 positive, negative, and fractional: ^ (-|+)? \d+ (. \d+)? $
9 positive real numbers with two decimal places: ^[0-9]+ (. [ 0-9]{2})? $
10 positive real numbers with a decimal position: ^[0-9]+ (. [ 0-9]{1,3})? $
11 non-zero positive integers: ^[1-9]\d$ or ^ ([1-9][0-9]) {1,3}$ or ^+? [1-9] [0-9]*$
12 non-zero negative integer: ^-[1-9][]0-9 "$ or ^-[1-9]\d$
13 non-negative integers: ^\d+$ or ^[1-9]\d*|0$
14 Non-positive integers: ^-[1-9]\d*|0$ or ^ ((-\d+) | ( 0+)) $
15 non-negative floating point number: ^\d+ (. \d+)? $ or ^[1-9]\d.\d|0.\d[1-9]\d|0?. 0+|0$
16 Non-positive floating-point number: ^ ((-\d+ (. \d+)?) | (0+ (. 0+)?)) $ or ^ (-([1-9]\d.\d|0.\d[1-9]\d)) | 0+|0$
17 Positive floating point number: ^[1-9]\d.\d|0.\d[1-9]\d$ or ^ ([0-9]+.[ 0-9][1-9][0-9]) | ([0-9][1-9][0-9]. [0-9]+) | ([0-9][1-9][0-9])) $
18 Negative floating point number: ^-([1-9]\d.\d|0.\d[1-9]\d) $ or ^ (-([0-9]+.[ 0-9][1-9][0-9]) | ([0-9][1-9][0-9]. [0-9]+) | ([0-9][1-9][0-9]))) $
19 floating-point number: ^ (-?\d+) (. \d+)? $ or ^-? ([1-9]\d.\d|0.\d[1-9]\d|0?. 0+|0) $
An expression that verifies a number