php - How to get the default languge from the ICU library by Country Code -

en_us gives me en english it's in code

i need us return en english or 'de' return de german

echo locale::getprimarylanguage('en_us'); echo locale::getprimarylanguage('us'); 

both of above should output en, latter outputs us.

getprimarylanguage not icu function have no idea how it's implemented. in icu call uloc_addlikelysubtags expand und_us (you put und unknown before region code us) en_us or und_de de_de - , then, calling uloc_getlanguage return en, de, etc.

your result of us us due us being interpreted language code. try und_us see behavior is.