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1 Write a Regular Expression that will match a date that follows the following s

ID: 3714920 • Letter: 1

Question

1 Write a Regular Expression that will match a date that follows the following standard “DD-MM-YYYY”

2  Write a Rregular Expression matching a decimal with a precision of 4.

3 What does the following Regular Expression match?

/[a-zA-Z][a-zA-Z]*/

True

False

4  Write a Regular Expression that will match a traditional SSN.

5 What does the following Regular Expression match?

/^CST-3523$/

6 What is use of Regular Expressions?

7 What the following Regular Expression matches?

/Fox>/

8 What is Regular Expressions?

9 What the following Regular Expression matches?

/^[^0-9]$/

Explanation / Answer

1.

d{1,2}-d{1,2}-d{4}

d{1,2} - matches 1 or 2 digits

- - matches -

d{4} - matches 4 digits

22-2-2018 - valid

02-02-1992 - valid

2-3-1923 - valid

12-3-122 - invalid

123-03-1243 - invalid

2.

d*.d{4}

d* - matches one or more number of digits

. - matches .

d{4} - matches 4 digits

0.3242 - valid

1213.2222 - valid

1233.22 - invalid

11.111 - invalid

.2222 - valid

4.4444 - valid

3.

[a-zA-Z][a-zA-Z]*

[a-zA-Z] - matches any character in set a-z and A-Z

[a-zA-Z]* - matches any character in set a-z and A-Z , * means 0 or more number of times

acBBBBB - valid

a - valid

Zaa - valid

Z - valid

4.

SSN is a 9 digit number in format AAA-BB-CCCC

d{3}-d{2}-d{4}

111-22-3333 - valid

aa1-33-2222 - invalid

1-11-1111 - invalid

111-1-1111 - invalid

111-11-111 - invalid

111-11-1111 - valid

999-99-9999 - valid

5.

^CST-3523$ - matches literally this CST-3523 nothing else

6.

Regular expression are used in searching , pattern matching , parsing in computer programming.

For example -

In some program, regular expression can be made to validate SSN, phone number, URl, email Id etc.

7.

/Fox>/ - matches Fox> in a string

8.

Regular expression is a pattern consisting of letters, special symbols, digits etc.

which is to be searched from a string or a phrase.

9.

^[^0-9]$ - matches a character other than list 0-9