72}
73
74String.prototype.fixNbsp = function () {
75 return this.replace(/\xA0/g, ' ') 76}
77
78String.prototype.capitalise = function () {1298}
1299
1300function nuAddSlashes (s) {
1301 return String(s).replace(/[\\"']/g, '\\$&').replace(/\u0000/g, '\\0')1302}
1303
1304function nuOpenTab (i) {It is recommended to use the u flag with regular expressions.
The u flag has two effects:
- It enables correct handling of UTF-16 surrogate pairs.
- It ensures the correct behavior of regex character ranges.
/^[👍]$/.test("👍") //→ false
/^[👍]$/u.test("👍") //→ true
For historical reasons, JavaScript regular expressions tolerate syntax errors.
For example, /\w{1, 2/ is a regex that would throw a syntax error, but JavaScript chooses not to.
It matches strings such as "a{1, 2" instead.
This behaviour is defined in Annex B of the Javascript specification.
The u flag disables the recovering logic Annex B of the Javascript specification.
This way, you can find errors early.
It can therefore be thought of as a "strict mode" for RegEx literals.
This issue is raised when:
- A regular expression contains unicode property escapes i.e \p{<property-name>}
- A regular expression contains 4 bytes characters like emojis or some special characters
Bad Practice
const a = /aaa/
const b = /bbb/gi
const c = new RegExp("ccc")
const d = new RegExp("ddd", "gi")
Recommended
const a = /aaa/u
const b = /bbb/giu
const c = new RegExp("ccc", "u")
const d = new RegExp("ddd", "giu")
// This rule ignores RegExp calls if the flags are not a compile time constant.
function f(flags) {
return new RegExp("eee", flags)
}