The question is simple: I have a string
str, how do I check ifstris one single emoji, and nothing else? Additionally I would prefer not using another library.Match
"","⛹♂️","3️⃣"but not"a","",""
I'm having trouble finding a solution but here are some things I've tried so far:
Attempted Solution 1 - Play around lengths and ... operator
I learned that emojis occupy more than one byte, some even occupy 4 bytes, or more... and we can measure that via the string's length property:
console.log("".length); // 2
console.log("️".length); // 3
console.log("⛹♂️".length); // 6
Then I found out that the ... operator takes this into account and correctly separates emojis in the array - I could then see the resulting array's length property and detect if they were different.
str = "⛹♂️";
if (str.length !== [...str].length) {
// is emoji?
} else {
// is not emoji
}
But this doesn't check for other multi-byte characters such as whose length is 2. Plus some emojis were still getting separated in a weird.
Attempted Solution 2 - Regex, regular expressions
Of course regex would be a thing to look into but I've yet to find a viable solution.
This answer's regex \u00a9|\u00ae|[\u2000-\u3300]|\ud83c[\ud000-\udfff]|\ud83d[\ud000-\udfff]|\ud83e[\ud000-\udfff] works perfectly fine to detect if a string has any emojis, but applied to my situation it produces a lot of problems. Here are my tests:
Part A - Without start/end of string regex (^ and $)
- 2A.1
str.match(regex)is very inconsistent, it breaks down some emojis and some other unusable. I don't see a way to find out if it even contains non-emoji characters or if it contains more than one emoji:
let regex = /(\u00a9|\u00ae|[\u2000-\u3300]|\ud83c[\ud000-\udfff]|\ud83d[\ud000-\udfff]|\ud83e[\ud000-\udfff])/;
console.log("5️⃣".match(regex)); // [ '⃣', '⃣', index: 2, input: '5️⃣' ]
console.log("".match(regex)); // [ '', '', index: 0, input: '' ]
console.log("️️".match(regex)); // [ '', '', index: 0, input: '️️' ]
console.log("a⛅".match(regex)); // [ '⛅', '⛅', index: 1, input: 'a⛅' ]
- 2A.2
regex.test(str)returns true whenever an emoji is included in the string, which isn't the behaviour I'm looking for:
let regex = /(\u00a9|\u00ae|[\u2000-\u3300]|\ud83c[\ud000-\udfff]|\ud83d[\ud000-\udfff]|\ud83e[\ud000-\udfff])/;
console.log(regex.test("5️⃣")); // true - correct
console.log(regex.test("a")); // false - correct
console.log(regex.test("️️")); // true - should be false
console.log(regex.test("hello ⛅!")); // true - should be false
Part B - With start/end of string regex (^ and $)
- 2B.1
str.match(regex)returnsnullon certain emojis for some reason. I have no clue why but I'm assuming it has some relation as to whystr.match(regex)would break down these emojis in Part A:
let regex = /^(\u00a9|\u00ae|[\u2000-\u3300]|\ud83c[\ud000-\udfff]|\ud83d[\ud000-\udfff]|\ud83e[\ud000-\udfff])$/;
console.log("5️⃣".match(regex)); // null
console.log("".match(regex)); // [ '', '', index: 0, input: '' ]
console.log("️".match(regex)); // null
console.log("⛅".match(regex)); // [ '⛅', '⛅', index: 1, input: 'a⛅' ]
console.log("".match(regex)); // null
- 2B.2
regex.test(str)will returnfalseon the same emojis where it would returnnullonstr.match(regex):
let regex = /^(\u00a9|\u00ae|[\u2000-\u3300]|\ud83c[\ud000-\udfff]|\ud83d[\ud000-\udfff]|\ud83e[\ud000-\udfff])$/;
console.log(regex.test("5️⃣")); // false - should be true
console.log(regex.test("")); // true - correct
console.log(regex.test("️")); // false - should be true
console.log(regex.test("⛅")); // true - correct
console.log(regex.test("")); // false - correct
Part C - Other regular expressions
- I found this one but it gives similar inconsistencies, although not the same
/(?:[\u2700-\u27bf]|(?:\ud83c[\udde6-\uddff]){2}|[\ud800-\udbff][\udc00-\udfff]|[\u0023-\u0039]\ufe0f?\u20e3|\u3299|\u3297|\u303d|\u3030|\u24c2|\ud83c[\udd70-\udd71]|\ud83c[\udd7e-\udd7f]|\ud83c\udd8e|\ud83c[\udd91-\udd9a]|\ud83c[\udde6-\uddff]|[\ud83c[\ude01\uddff]|\ud83c[\ude01-\ude02]|\ud83c\ude1a|\ud83c\ude2f|[\ud83c[\ude32\ude02]|\ud83c\ude1a|\ud83c\ude2f|\ud83c[\ude32-\ude3a]|[\ud83c[\ude50\ude3a]|\ud83c[\ude50-\ude51]|\u203c|\u2049|[\u25aa-\u25ab]|\u25b6|\u25c0|[\u25fb-\u25fe]|\u00a9|\u00ae|\u2122|\u2139|\ud83c\udc04|[\u2600-\u26FF]|\u2b05|\u2b06|\u2b07|\u2b1b|\u2b1c|\u2b50|\u2b55|\u231a|\u231b|\u2328|\u23cf|[\u23e9-\u23f3]|[\u23f8-\u23fa]|\ud83c\udccf|\u2934|\u2935|[\u2190-\u21ff])/g:
let regex = /^(?:[\u2700-\u27bf]|(?:\ud83c[\udde6-\uddff]){2}|[\ud800-\udbff][\udc00-\udfff]|[\u0023-\u0039]\ufe0f?\u20e3|\u3299|\u3297|\u303d|\u3030|\u24c2|\ud83c[\udd70-\udd71]|\ud83c[\udd7e-\udd7f]|\ud83c\udd8e|\ud83c[\udd91-\udd9a]|\ud83c[\udde6-\uddff]|[\ud83c[\ude01\uddff]|\ud83c[\ude01-\ude02]|\ud83c\ude1a|\ud83c\ude2f|[\ud83c[\ude32\ude02]|\ud83c\ude1a|\ud83c\ude2f|\ud83c[\ude32-\ude3a]|[\ud83c[\ude50\ude3a]|\ud83c[\ude50-\ude51]|\u203c|\u2049|[\u25aa-\u25ab]|\u25b6|\u25c0|[\u25fb-\u25fe]|\u00a9|\u00ae|\u2122|\u2139|\ud83c\udc04|[\u2600-\u26FF]|\u2b05|\u2b06|\u2b07|\u2b1b|\u2b1c|\u2b50|\u2b55|\u231a|\u231b|\u2328|\u23cf|[\u23e9-\u23f3]|[\u23f8-\u23fa]|\ud83c\udccf|\u2934|\u2935|[\u2190-\u21ff])$/g
console.log(regex.test("5️⃣")); // true - correct
console.log(regex.test("")); // false - should be true
console.log(regex.test("️")); // false - should be true
console.log(regex.test("⛅")); // true - correct
console.log(regex.test("")); // false - correct
- Also this breaks horribly (second test changes based on first test?)
let regex = /^(?:[\u2700-\u27bf]|(?:\ud83c[\udde6-\uddff]){2}|[\ud800-\udbff][\udc00-\udfff]|[\u0023-\u0039]\ufe0f?\u20e3|\u3299|\u3297|\u303d|\u3030|\u24c2|\ud83c[\udd70-\udd71]|\ud83c[\udd7e-\udd7f]|\ud83c\udd8e|\ud83c[\udd91-\udd9a]|\ud83c[\udde6-\uddff]|[\ud83c[\ude01\uddff]|\ud83c[\ude01-\ude02]|\ud83c\ude1a|\ud83c\ude2f|[\ud83c[\ude32\ude02]|\ud83c\ude1a|\ud83c\ude2f|\ud83c[\ude32-\ude3a]|[\ud83c[\ude50\ude3a]|\ud83c[\ude50-\ude51]|\u203c|\u2049|[\u25aa-\u25ab]|\u25b6|\u25c0|[\u25fb-\u25fe]|\u00a9|\u00ae|\u2122|\u2139|\ud83c\udc04|[\u2600-\u26FF]|\u2b05|\u2b06|\u2b07|\u2b1b|\u2b1c|\u2b50|\u2b55|\u231a|\u231b|\u2328|\u23cf|[\u23e9-\u23f3]|[\u23f8-\u23fa]|\ud83c\udccf|\u2934|\u2935|[\u2190-\u21ff])$/g
console.log(regex.test("⛹♂️")); // false
console.log(regex.test("⛅")); // true
let regex = /^(?:[\u2700-\u27bf]|(?:\ud83c[\udde6-\uddff]){2}|[\ud800-\udbff][\udc00-\udfff]|[\u0023-\u0039]\ufe0f?\u20e3|\u3299|\u3297|\u303d|\u3030|\u24c2|\ud83c[\udd70-\udd71]|\ud83c[\udd7e-\udd7f]|\ud83c\udd8e|\ud83c[\udd91-\udd9a]|\ud83c[\udde6-\uddff]|[\ud83c[\ude01\uddff]|\ud83c[\ude01-\ude02]|\ud83c\ude1a|\ud83c\ude2f|[\ud83c[\ude32\ude02]|\ud83c\ude1a|\ud83c\ude2f|\ud83c[\ude32-\ude3a]|[\ud83c[\ude50\ude3a]|\ud83c[\ude50-\ude51]|\u203c|\u2049|[\u25aa-\u25ab]|\u25b6|\u25c0|[\u25fb-\u25fe]|\u00a9|\u00ae|\u2122|\u2139|\ud83c\udc04|[\u2600-\u26FF]|\u2b05|\u2b06|\u2b07|\u2b1b|\u2b1c|\u2b50|\u2b55|\u231a|\u231b|\u2328|\u23cf|[\u23e9-\u23f3]|[\u23f8-\u23fa]|\ud83c\udccf|\u2934|\u2935|[\u2190-\u21ff])$/g;
console.log(regex.test("⛹")); // true
console.log(regex.test("⛅")); // false
Is there a way around all this emoji/unicode/regex mess? Are libraries/apis the only way? How do they do it?
