Regular expression that matches a string with optional leading and trailing spaces and a hyphen in the middle

Question

Regular expression that matches a string with optional leading and trailing spaces and a hyphen in the middle

I need help creating a JavaScript regex that can match strings like the examples provided. The string may have whitespace at the front, back, or both but not within the string itself.

Examples:

'Z5LW-KRT2'       MATCH
' Z5LW-krt2'      MATCH
'Z5LW-KRT2 '      MATCH
' Z5LW-KRT2 '     MATCH

' Z5LW-K RT2 '    NO MATCH

Currently, I have a regex pattern that matches strings without any whitespace anywhere. However, I'm struggling to modify it to include whitespace at the beginning or end but exclude it within the string as shown in the examples.

^[A-Za-z0-9\-]+$

javascript regex

Answer 1

Answer №1

For better space matching, consider adding \s* to the regex pattern. This would make the revised regex appear as: ^\s*[A-Za-z0-9\-]+\s*$. If desired, you can further simplify it to ^\s*[\w\-]+\s*$ by utilizing the built-in \w class.

Answer 2

For better space matching, consider adding \s* to the regex pattern. This would make the revised regex appear as: ^\s*[A-Za-z0-9\-]+\s*$. If desired, you can further simplify it to ^\s*[\w\-]+\s*$ by utilizing the built-in \w class.

Answer 3

Answer №2

Whether ^\s*\S+\s*$ or ^\s*[A-Za-z0-9\-]+\s*$ will suit your requirements:

^: beginning of the line
\s*: optional spaces
\S+: at least one non-whitespace character OR
[A-Za-z0-9\-]: matches specific character classes
\s*: optional spaces
$: end of the line

let tests = [ 'Z5LW-KRT2'  //     MATCH
            , ' Z5LW-krt2' //     MATCH
            , 'Z5LW-KRT2 ' //     MATCH
            , ' Z5LW-KRT2 ' //    MATCH
            , ' Z5LW-K RT2 ' //   NO MATCH
            ]
            
let regex1 = /^\s*\S+\s*$/
let regex2 = /^\s*[A-Za-z0-9\-]+\s*$/

for (test of tests) {
  console.log(`[${test}] regex1: ${test.match(regex1)?'MATCH':'NO MATCH'}, regex2: ${test.match(regex2)?'MATCH':'NO MATCH'}`)
}

Answer 4

Whether ^\s*\S+\s*$ or ^\s*[A-Za-z0-9\-]+\s*$ will suit your requirements:

^: beginning of the line
\s*: optional spaces
\S+: at least one non-whitespace character OR
[A-Za-z0-9\-]: matches specific character classes
\s*: optional spaces
$: end of the line

let tests = [ 'Z5LW-KRT2'  //     MATCH
            , ' Z5LW-krt2' //     MATCH
            , 'Z5LW-KRT2 ' //     MATCH
            , ' Z5LW-KRT2 ' //    MATCH
            , ' Z5LW-K RT2 ' //   NO MATCH
            ]
            
let regex1 = /^\s*\S+\s*$/
let regex2 = /^\s*[A-Za-z0-9\-]+\s*$/

for (test of tests) {
  console.log(`[${test}] regex1: ${test.match(regex1)?'MATCH':'NO MATCH'}, regex2: ${test.match(regex2)?'MATCH':'NO MATCH'}`)
}

Regular expression that matches a string with optional leading and trailing spaces and a hyphen in the middle

Answer №1

Answer №2

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