regex - any number of digits + digit or [a-z]
I am trying to write a regular expresion that checks if a string starts with a number of digits (at least one), and then immediately ends with a single letter or a digit.
So:
29cis fine
29is fine
2425315651252fsawfails
24241jl.421cfails
cfails
The regex I have so far is (^d+)([a-z]{1}|d) which passes the 29, 20c, but also passes stuff like 29cdsd.
What am I doing wrong?
regex
asked Nov 23 '18 at 12:55
Miha ŠušteršičMiha Šušteršič
3,711104479
add a comment |
I am trying to write a regular expresion that checks if a string starts with a number of digits (at least one), and then immediately ends with a single letter or a digit.
So:
29cis fine
29is fine
2425315651252fsawfails
24241jl.421cfails
cfails
The regex I have so far is (^d+)([a-z]{1}|d) which passes the 29, 20c, but also passes stuff like 29cdsd.
What am I doing wrong?
regex
asked Nov 23 '18 at 12:55
Miha ŠušteršičMiha Šušteršič
3,711104479
Please let know ifaand1are valid inputs.
– Wiktor Stribiżew
Nov 23 '18 at 13:05
add a comment |
I am trying to write a regular expresion that checks if a string starts with a number of digits (at least one), and then immediately ends with a single letter or a digit.
So:
29cis fine
29is fine
2425315651252fsawfails
24241jl.421cfails
cfails
The regex I have so far is (^d+)([a-z]{1}|d) which passes the 29, 20c, but also passes stuff like 29cdsd.
What am I doing wrong?
regex
asked Nov 23 '18 at 12:55
Miha ŠušteršičMiha Šušteršič
3,711104479
I am trying to write a regular expresion that checks if a string starts with a number of digits (at least one), and then immediately ends with a single letter or a digit.
So:
29cis fine
29is fine
2425315651252fsawfails
24241jl.421cfails
cfails
The regex I have so far is (^d+)([a-z]{1}|d) which passes the 29, 20c, but also passes stuff like 29cdsd.
What am I doing wrong?
regex
regex
asked Nov 23 '18 at 12:55
Miha ŠušteršičMiha Šušteršič
3,711104479
asked Nov 23 '18 at 12:55
Miha ŠušteršičMiha Šušteršič
3,711104479
edited Nov 23 '18 at 13:15
Miha Šušteršič
asked Nov 23 '18 at 12:55
Miha ŠušteršičMiha Šušteršič
3,711104479
asked Nov 23 '18 at 12:55
Miha ŠušteršičMiha Šušteršič
3,711104479
asked Nov 23 '18 at 12:55
Miha ŠušteršičMiha Šušteršič
3,711104479
3,711104479
Please let know ifaand1are valid inputs.
– Wiktor Stribiżew
Nov 23 '18 at 13:05
add a comment |
Please let know ifaand1are valid inputs.
– Wiktor Stribiżew
Nov 23 '18 at 13:05
Please let know if
a and 1 are valid inputs.– Wiktor Stribiżew
Nov 23 '18 at 13:05
Please let know if
a and 1 are valid inputs.– Wiktor Stribiżew
Nov 23 '18 at 13:05
add a comment |
5 Answers
5
active
oldest
votes
Your (^d+)([a-z]{1}|d) passes 29cdsd because it matches 1 or more digits at the start of the string followed with 1 letter or 1 digit, and allows anything right after.
Use
^[0-9]+[a-z0-9]?$
See regex demo
Details
^- start of string
[0-9]+- any 1 or more digits
[a-z0-9]?- 1 or 0 lowercase ASCII letters or digits
$- end of string.
answered Nov 23 '18 at 12:56
Wiktor StribiżewWiktor Stribiżew
310k16131206
1
Wouldn't this allow the string to be a single character a-z?
– ohaal
Nov 23 '18 at 12:59
@ohaal Yes, these are the requirements. a string starts with any number of digits, and then immediately ends with a single letter or a digit. Any means 0 or more.
– Wiktor Stribiżew
Nov 23 '18 at 12:59
Ah, yes, he says "any number of digits", so I guess that means 0 or more. It is me who has misunderstood the question.
– ohaal
Nov 23 '18 at 13:00
@ohaal Well, we need confirmation from OP. Your^d+[a-z]?$solution might be actually what OP wants in the end if there is a requirement to disallow just one letter strings. I prefer[0-9]here because OP did not specify the regex flavor. Not all flavors supportd.
– Wiktor Stribiżew
Nov 23 '18 at 13:03
Ugh sry, yes @ohaal is correct - the string cannot start with a character. Edited the question so it is more clear.
– Miha Šušteršič
Nov 23 '18 at 13:14
|
show 1 more comment
This should follow your rules exactly.
^d+[a-z]?$
answered Nov 23 '18 at 12:57
ohaalohaal
4,69222646
add a comment |
if "any number of digits" might be zero ^d*w$
answered Nov 23 '18 at 13:15
ekvalizerekvalizer
214
add a comment |
You could add an anchor $ to assert the end of the line and you can omit the {1} part:
^(d+)([a-z]|d)$
In your regex you are matching a minimum of 2 characters .If you don't need the capturing groups, this could also be written as:
^d+[a-zd]$
Regex demo
That would match:
^Assert the start of the string
d+Match 1+ digits
[a-zd]A character class which matches a-z or a digit
$Assert the end of the string
answered Nov 23 '18 at 13:13
The fourth birdThe fourth bird
21.1k71326
add a comment |
^ - start of string
d* - any amount of digits, 0 or more
[a-zA-z] - a lowercase and uppercase ASCII letters.
$ - end of string
answered Nov 23 '18 at 13:13
GK DevloperGK Devloper
12
add a comment |
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5 Answers
5
active
oldest
votes
5 Answers
5
active
oldest
votes
active
oldest
votes
active
oldest
votes
Your (^d+)([a-z]{1}|d) passes 29cdsd because it matches 1 or more digits at the start of the string followed with 1 letter or 1 digit, and allows anything right after.
Use
^[0-9]+[a-z0-9]?$
See regex demo
Details
^- start of string
[0-9]+- any 1 or more digits
[a-z0-9]?- 1 or 0 lowercase ASCII letters or digits
$- end of string.
answered Nov 23 '18 at 12:56
Wiktor StribiżewWiktor Stribiżew
310k16131206
1
Wouldn't this allow the string to be a single character a-z?
– ohaal
Nov 23 '18 at 12:59
@ohaal Yes, these are the requirements. a string starts with any number of digits, and then immediately ends with a single letter or a digit. Any means 0 or more.
– Wiktor Stribiżew
Nov 23 '18 at 12:59
Ah, yes, he says "any number of digits", so I guess that means 0 or more. It is me who has misunderstood the question.
– ohaal
Nov 23 '18 at 13:00
@ohaal Well, we need confirmation from OP. Your^d+[a-z]?$solution might be actually what OP wants in the end if there is a requirement to disallow just one letter strings. I prefer[0-9]here because OP did not specify the regex flavor. Not all flavors supportd.
– Wiktor Stribiżew
Nov 23 '18 at 13:03
Ugh sry, yes @ohaal is correct - the string cannot start with a character. Edited the question so it is more clear.
– Miha Šušteršič
Nov 23 '18 at 13:14
|
show 1 more comment
Your (^d+)([a-z]{1}|d) passes 29cdsd because it matches 1 or more digits at the start of the string followed with 1 letter or 1 digit, and allows anything right after.
Use
^[0-9]+[a-z0-9]?$
See regex demo
Details
^- start of string
[0-9]+- any 1 or more digits
[a-z0-9]?- 1 or 0 lowercase ASCII letters or digits
$- end of string.
answered Nov 23 '18 at 12:56
Wiktor StribiżewWiktor Stribiżew
310k16131206
1
Wouldn't this allow the string to be a single character a-z?
– ohaal
Nov 23 '18 at 12:59
@ohaal Yes, these are the requirements. a string starts with any number of digits, and then immediately ends with a single letter or a digit. Any means 0 or more.
– Wiktor Stribiżew
Nov 23 '18 at 12:59
Ah, yes, he says "any number of digits", so I guess that means 0 or more. It is me who has misunderstood the question.
– ohaal
Nov 23 '18 at 13:00
@ohaal Well, we need confirmation from OP. Your^d+[a-z]?$solution might be actually what OP wants in the end if there is a requirement to disallow just one letter strings. I prefer[0-9]here because OP did not specify the regex flavor. Not all flavors supportd.
– Wiktor Stribiżew
Nov 23 '18 at 13:03
Ugh sry, yes @ohaal is correct - the string cannot start with a character. Edited the question so it is more clear.
– Miha Šušteršič
Nov 23 '18 at 13:14
|
show 1 more comment
Your (^d+)([a-z]{1}|d) passes 29cdsd because it matches 1 or more digits at the start of the string followed with 1 letter or 1 digit, and allows anything right after.
Use
^[0-9]+[a-z0-9]?$
See regex demo
Details
^- start of string
[0-9]+- any 1 or more digits
[a-z0-9]?- 1 or 0 lowercase ASCII letters or digits
$- end of string.
answered Nov 23 '18 at 12:56
Wiktor StribiżewWiktor Stribiżew
310k16131206
Your (^d+)([a-z]{1}|d) passes 29cdsd because it matches 1 or more digits at the start of the string followed with 1 letter or 1 digit, and allows anything right after.
Use
^[0-9]+[a-z0-9]?$
See regex demo
Details
^- start of string
[0-9]+- any 1 or more digits
[a-z0-9]?- 1 or 0 lowercase ASCII letters or digits
$- end of string.
answered Nov 23 '18 at 12:56
Wiktor StribiżewWiktor Stribiżew
310k16131206
edited Nov 23 '18 at 13:15
answered Nov 23 '18 at 12:56
Wiktor StribiżewWiktor Stribiżew
310k16131206
answered Nov 23 '18 at 12:56
Wiktor StribiżewWiktor Stribiżew
310k16131206
answered Nov 23 '18 at 12:56
Wiktor StribiżewWiktor Stribiżew
310k16131206
310k16131206
1
Wouldn't this allow the string to be a single character a-z?
– ohaal
Nov 23 '18 at 12:59
@ohaal Yes, these are the requirements. a string starts with any number of digits, and then immediately ends with a single letter or a digit. Any means 0 or more.
– Wiktor Stribiżew
Nov 23 '18 at 12:59
Ah, yes, he says "any number of digits", so I guess that means 0 or more. It is me who has misunderstood the question.
– ohaal
Nov 23 '18 at 13:00
@ohaal Well, we need confirmation from OP. Your^d+[a-z]?$solution might be actually what OP wants in the end if there is a requirement to disallow just one letter strings. I prefer[0-9]here because OP did not specify the regex flavor. Not all flavors supportd.
– Wiktor Stribiżew
Nov 23 '18 at 13:03
Ugh sry, yes @ohaal is correct - the string cannot start with a character. Edited the question so it is more clear.
– Miha Šušteršič
Nov 23 '18 at 13:14
|
show 1 more comment
1
Wouldn't this allow the string to be a single character a-z?
– ohaal
Nov 23 '18 at 12:59
@ohaal Yes, these are the requirements. a string starts with any number of digits, and then immediately ends with a single letter or a digit. Any means 0 or more.
– Wiktor Stribiżew
Nov 23 '18 at 12:59
Ah, yes, he says "any number of digits", so I guess that means 0 or more. It is me who has misunderstood the question.
– ohaal
Nov 23 '18 at 13:00
@ohaal Well, we need confirmation from OP. Your^d+[a-z]?$solution might be actually what OP wants in the end if there is a requirement to disallow just one letter strings. I prefer[0-9]here because OP did not specify the regex flavor. Not all flavors supportd.
– Wiktor Stribiżew
Nov 23 '18 at 13:03
Ugh sry, yes @ohaal is correct - the string cannot start with a character. Edited the question so it is more clear.
– Miha Šušteršič
Nov 23 '18 at 13:14
1
1
Wouldn't this allow the string to be a single character a-z?
– ohaal
Nov 23 '18 at 12:59
Wouldn't this allow the string to be a single character a-z?
– ohaal
Nov 23 '18 at 12:59
@ohaal Yes, these are the requirements. a string starts with any number of digits, and then immediately ends with a single letter or a digit. Any means 0 or more.
– Wiktor Stribiżew
Nov 23 '18 at 12:59
@ohaal Yes, these are the requirements. a string starts with any number of digits, and then immediately ends with a single letter or a digit. Any means 0 or more.
– Wiktor Stribiżew
Nov 23 '18 at 12:59
Ah, yes, he says "any number of digits", so I guess that means 0 or more. It is me who has misunderstood the question.
– ohaal
Nov 23 '18 at 13:00
Ah, yes, he says "any number of digits", so I guess that means 0 or more. It is me who has misunderstood the question.
– ohaal
Nov 23 '18 at 13:00
@ohaal Well, we need confirmation from OP. Your
^d+[a-z]?$ solution might be actually what OP wants in the end if there is a requirement to disallow just one letter strings. I prefer [0-9] here because OP did not specify the regex flavor. Not all flavors support d.– Wiktor Stribiżew
Nov 23 '18 at 13:03
@ohaal Well, we need confirmation from OP. Your
^d+[a-z]?$ solution might be actually what OP wants in the end if there is a requirement to disallow just one letter strings. I prefer [0-9] here because OP did not specify the regex flavor. Not all flavors support d.– Wiktor Stribiżew
Nov 23 '18 at 13:03
Ugh sry, yes @ohaal is correct - the string cannot start with a character. Edited the question so it is more clear.
– Miha Šušteršič
Nov 23 '18 at 13:14
Ugh sry, yes @ohaal is correct - the string cannot start with a character. Edited the question so it is more clear.
– Miha Šušteršič
Nov 23 '18 at 13:14
|
show 1 more comment
This should follow your rules exactly.
^d+[a-z]?$
answered Nov 23 '18 at 12:57
ohaalohaal
4,69222646
add a comment |
This should follow your rules exactly.
^d+[a-z]?$
answered Nov 23 '18 at 12:57
ohaalohaal
4,69222646
add a comment |
This should follow your rules exactly.
^d+[a-z]?$
answered Nov 23 '18 at 12:57
ohaalohaal
4,69222646
This should follow your rules exactly.
^d+[a-z]?$
answered Nov 23 '18 at 12:57
ohaalohaal
4,69222646
answered Nov 23 '18 at 12:57
ohaalohaal
4,69222646
answered Nov 23 '18 at 12:57
ohaalohaal
4,69222646
answered Nov 23 '18 at 12:57
ohaalohaal
4,69222646
4,69222646
add a comment |
add a comment |
if "any number of digits" might be zero ^d*w$
answered Nov 23 '18 at 13:15
ekvalizerekvalizer
214
add a comment |
if "any number of digits" might be zero ^d*w$
answered Nov 23 '18 at 13:15
ekvalizerekvalizer
214
add a comment |
if "any number of digits" might be zero ^d*w$
answered Nov 23 '18 at 13:15
ekvalizerekvalizer
214
if "any number of digits" might be zero ^d*w$
answered Nov 23 '18 at 13:15
ekvalizerekvalizer
214
answered Nov 23 '18 at 13:15
ekvalizerekvalizer
214
answered Nov 23 '18 at 13:15
ekvalizerekvalizer
214
answered Nov 23 '18 at 13:15
ekvalizerekvalizer
214
214
add a comment |
add a comment |
You could add an anchor $ to assert the end of the line and you can omit the {1} part:
^(d+)([a-z]|d)$
In your regex you are matching a minimum of 2 characters .If you don't need the capturing groups, this could also be written as:
^d+[a-zd]$
Regex demo
That would match:
^Assert the start of the string
d+Match 1+ digits
[a-zd]A character class which matches a-z or a digit
$Assert the end of the string
answered Nov 23 '18 at 13:13
The fourth birdThe fourth bird
21.1k71326
add a comment |
You could add an anchor $ to assert the end of the line and you can omit the {1} part:
^(d+)([a-z]|d)$
In your regex you are matching a minimum of 2 characters .If you don't need the capturing groups, this could also be written as:
^d+[a-zd]$
Regex demo
That would match:
^Assert the start of the string
d+Match 1+ digits
[a-zd]A character class which matches a-z or a digit
$Assert the end of the string
answered Nov 23 '18 at 13:13
The fourth birdThe fourth bird
21.1k71326
add a comment |
You could add an anchor $ to assert the end of the line and you can omit the {1} part:
^(d+)([a-z]|d)$
In your regex you are matching a minimum of 2 characters .If you don't need the capturing groups, this could also be written as:
^d+[a-zd]$
Regex demo
That would match:
^Assert the start of the string
d+Match 1+ digits
[a-zd]A character class which matches a-z or a digit
$Assert the end of the string
answered Nov 23 '18 at 13:13
The fourth birdThe fourth bird
21.1k71326
You could add an anchor $ to assert the end of the line and you can omit the {1} part:
^(d+)([a-z]|d)$
In your regex you are matching a minimum of 2 characters .If you don't need the capturing groups, this could also be written as:
^d+[a-zd]$
Regex demo
That would match:
^Assert the start of the string
d+Match 1+ digits
[a-zd]A character class which matches a-z or a digit
$Assert the end of the string
answered Nov 23 '18 at 13:13
The fourth birdThe fourth bird
21.1k71326
edited Nov 23 '18 at 13:27
answered Nov 23 '18 at 13:13
The fourth birdThe fourth bird
21.1k71326
answered Nov 23 '18 at 13:13
The fourth birdThe fourth bird
21.1k71326
answered Nov 23 '18 at 13:13
The fourth birdThe fourth bird
21.1k71326
21.1k71326
add a comment |
add a comment |
^ - start of string
d* - any amount of digits, 0 or more
[a-zA-z] - a lowercase and uppercase ASCII letters.
$ - end of string
answered Nov 23 '18 at 13:13
GK DevloperGK Devloper
12
add a comment |
^ - start of string
d* - any amount of digits, 0 or more
[a-zA-z] - a lowercase and uppercase ASCII letters.
$ - end of string
answered Nov 23 '18 at 13:13
GK DevloperGK Devloper
12
add a comment |
^ - start of string
d* - any amount of digits, 0 or more
[a-zA-z] - a lowercase and uppercase ASCII letters.
$ - end of string
answered Nov 23 '18 at 13:13
GK DevloperGK Devloper
12
^ - start of string
d* - any amount of digits, 0 or more
[a-zA-z] - a lowercase and uppercase ASCII letters.
$ - end of string
answered Nov 23 '18 at 13:13
GK DevloperGK Devloper
12
edited Nov 23 '18 at 13:21
answered Nov 23 '18 at 13:13
GK DevloperGK Devloper
12
answered Nov 23 '18 at 13:13
GK DevloperGK Devloper
12
answered Nov 23 '18 at 13:13
GK DevloperGK Devloper
12
12
add a comment |
add a comment |
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Please let know if
aand1are valid inputs.– Wiktor Stribiżew
Nov 23 '18 at 13:05