Anchors in JavaScript

^       Start of string
$       End of string
\b      Word boundary
\B      Not a word boundary

// Multi-line mode (m flag)
^       Start of line
$       End of line

// Examples
/^hello/.test("hello world")     // true
/world$/.test("hello world")     // true
/^hello$/.test("hello")          // true (exact match)
/\bcat\b/.test("cat in hat")     // true (whole word)
/\bcat\b/.test("scatter")        // false
/\Bcat/.test("scatter")          // true (inside word)

// Multi-line examples
const text = "line1\nline2"
/^line2/m.test(text)             // true (with m flag)
/^line2/.test(text)              // false (without m flag)