仅在字符串的开头/结尾匹配正则表达式

Question

As per the title, I'm trying to use a .match() function on a string to only match with instances that occur at the start or end of that string (but no where in the middle).

For example, on the word "test":

x = "1 TEST 1"
x1 = "TEST 1"
x2 = "1 TEST"
x3 = "TEST"

Only x1, x2 and x3 should match the regex. Currently, I have:

.toUpperCase().match(/(TEST)/)

Which will match every instance of "test". I've tried using the ^ and $ modifiers, but they'll only match x3. This one however:`

.toUpperCase().match(/(TEST)$/)

Will match x2 and x3 only, with .toUpperCase().match(/^(TEST)/) matching x1 and x3 only.

Answer 1

Just match one or the other using | .

.toUpperCase().match(/^TEST|TEST$/)

Also note that you don't need to put parentheses around TEST .

Answer 2

/^TEST.*|.*TEST$/

this regex will match a line if it starts or ends with "TEST". add m to match multiple lines

Note: this regex will return the whole line