**Swift 5**
I combine answer from Oded and LC into a function.
```swift
func getCountryCode() -> String {
// get the country code, such as EG, US, etc.
guard let carrier = CTTelephonyNetworkInfo().subscriberCellularProvider, let countryCode = carrier.isoCountryCode else { return "" }
// list of available country phone prefix
let prefixCodes = ["AF": "93", "AE": "971", "AL": "355", "AN": "599", "AS":"1", "AD": "376", "AO": "244", "AI": "1", "AG":"1", "AR": "54","AM": "374", "AW": "297", "AU":"61", "AT": "43","AZ": "994", "BS": "1", "BH":"973", "BF": "226","BI": "257", "BD": "880", "BB": "1", "BY": "375", "BE":"32","BZ": "501", "BJ": "229", "BM": "1", "BT":"975", "BA": "387", "BW": "267", "BR": "55", "BG": "359", "BO": "591", "BL": "590", "BN": "673", "CC": "61", "CD":"243","CI": "225", "KH":"855", "CM": "237", "CA": "1", "CV": "238", "KY":"345", "CF":"236", "CH": "41", "CL": "56", "CN":"86","CX": "61", "CO": "57", "KM": "269", "CG":"242", "CK": "682", "CR": "506", "CU":"53", "CY":"537","CZ": "420", "DE": "49", "DK": "45", "DJ":"253", "DM": "1", "DO": "1", "DZ": "213", "EC": "593", "EG":"20", "ER": "291", "EE":"372","ES": "34", "ET": "251", "FM": "691", "FK": "500", "FO": "298", "FJ": "679", "FI":"358", "FR": "33", "GB":"44", "GF": "594", "GA":"241", "GS": "500", "GM":"220", "GE":"995","GH":"233", "GI": "350", "GQ": "240", "GR": "30", "GG": "44", "GL": "299", "GD":"1", "GP": "590", "GU": "1", "GT": "502", "GN":"224","GW": "245", "GY": "595", "HT": "509", "HR": "385", "HN":"504", "HU": "36", "HK": "852", "IR": "98", "IM": "44", "IL": "972", "IO":"246", "IS": "354", "IN": "91", "ID":"62", "IQ":"964", "IE": "353","IT":"39", "JM":"1", "JP": "81", "JO": "962", "JE":"44", "KP": "850", "KR": "82","KZ":"77", "KE": "254", "KI": "686", "KW": "965", "KG":"996","KN":"1", "LC": "1", "LV": "371", "LB": "961", "LK":"94", "LS": "266", "LR":"231", "LI": "423", "LT": "370", "LU": "352", "LA": "856", "LY":"218", "MO": "853", "MK": "389", "MG":"261", "MW": "265", "MY": "60","MV": "960", "ML":"223", "MT": "356", "MH": "692", "MQ": "596", "MR":"222", "MU": "230", "MX": "52","MC": "377", "MN": "976", "ME": "382", "MP": "1", "MS": "1", "MA":"212", "MM": "95", "MF": "590", "MD":"373", "MZ": "258", "NA":"264", "NR":"674", "NP":"977", "NL": "31","NC": "687", "NZ":"64", "NI": "505", "NE": "227", "NG": "234", "NU":"683", "NF": "672", "NO": "47","OM": "968", "PK": "92", "PM": "508", "PW": "680", "PF": "689", "PA": "507", "PG":"675", "PY": "595", "PE": "51", "PH": "63", "PL":"48", "PN": "872","PT": "351", "PR": "1","PS": "970", "QA": "974", "RO":"40", "RE":"262", "RS": "381", "RU": "7", "RW": "250", "SM": "378", "SA":"966", "SN": "221", "SC": "248", "SL":"232","SG": "65", "SK": "421", "SI": "386", "SB":"677", "SH": "290", "SD": "249", "SR": "597","SZ": "268", "SE":"46", "SV": "503", "ST": "239","SO": "252", "SJ": "47", "SY":"963", "TW": "886", "TZ": "255", "TL": "670", "TD": "235", "TJ": "992", "TH": "66", "TG":"228", "TK": "690", "TO": "676", "TT": "1", "TN":"216","TR": "90", "TM": "993", "TC": "1", "TV":"688", "UG": "256", "UA": "380", "US": "1", "UY": "598","UZ": "998", "VA":"379", "VE":"58", "VN": "84", "VG": "1", "VI": "1","VC":"1", "VU":"678", "WS": "685", "WF": "681", "YE": "967", "YT": "262","ZA": "27" , "ZM": "260", "ZW":"263"]
// get the prefix
let countryDialingCode = prefixCodes[countryCode.uppercased()] ?? ""
return countryDialingCode
}
```
**Swift**
let callingCodes = ["AD":"376","AE":"971","AF":"93","AG":"1","AI":"1","AL":"355","AM":"374","AN":"599","AO":"244","AR":"54","AS":"1","AT":"43","AU":"61","AW":"297","AZ":"994",
"BA":"387","BB":"1","BD":"880","BE":"32","BF":"226","BG":"359","BH":"973","BI":"257","BJ":"229","BL":"590","BM":"1","BN":"673","BO":"591","BR":"55","BS":"1","BT":"975","BW":"267","BY":"375","BZ":"501",
"CA":"1","CC":"61","CD":"243","CF":"236","CG":"242","CH":"41","CI":"225","CK":"682","CL":"56","CM":"237","CN":"86","CO":"57","CR":"506","CU":"53","CV":"238","CX":"61","CY":"537","CZ":"420",
"DE":"49","DJ":"253","DK":"45","DM":"1","DO":"1","DZ":"213",
"EC":"593","EE":"372","EG":"20","ER":"291","ES":"34","ET":"251",
"FI":"358","FJ":"679","FK":"500","FM":"691","FO":"298","FR":"33",
"GA":"241","GB":"44","GD":"1","GE":"995","GF":"594","GG":"44","GH":"233","GI":"350","GL":"299","GM":"220","GN":"224","GP":"590","GQ":"240","GR":"30","GS":"500","GT":"502","GU":"1","GW":"245","GY":"595",
"HK":"852","HN":"504","HR":"385","HT":"509","HU":"36","ID":"62","IE":"353",
"IL":"972","IM":"44","IN":"91","IO":"246","IQ":"964","IR":"98","IS":"354","IT":"39",
"JE":"44","JM":"1","JO":"962","JP":"81",
"KE":"254","KG":"996","KH":"855","KI":"686","KM":"269","KN":"1","KP":"850","KR":"82","KW":"965","KY":"345","KZ":"77",
"LA":"856","LB":"961","LC":"1","LI":"423","LK":"94","LR":"231","LS":"266","LT":"370","LU":"352","LV":"371","LY":"218",
"MA":"212","MC":"377","MD":"373","ME":"382","MF":"590","MG":"261","MH":"692","MK":"389","ML":"223","MM":"95","MN":"976","MO":"853","MP":"1","MQ":"596","MR":"222","MS":"1","MT":"356","MU":"230","MV":"960","MW":"265","MX":"52","MY":"60","MZ":"258",
"NA":"264","NC":"687","NE":"227","NF":"672","NG":"234","NI":"505","NL":"31","NO":"47","NP":"977","NR":"674","NU":"683","NZ":"64",
"OM":"968",
"PA":"507","PE":"51","PF":"689","PG":"675","PH":"63","PK":"92","PL":"48","PM":"508","PN":"872","PR":"1","PS":"970","PT":"351","PW":"680","PY":"595",
"QA":"974",
"RE":"262","RO":"40","RS":"381","RU":"7","RW":"250",
"SA":"966","SB":"677","SC":"248","SD":"249","SE":"46","SG":"65","SH":"290","SI":"386","SJ":"47","SK":"421","SL":"232","SM":"378","SN":"221","SO":"252","SR":"597","ST":"239","SV":"503","SY":"963","SZ":"268",
"TC":"1","TD":"235","TG":"228","TH":"66","TJ":"992","TK":"690","TL":"670","TM":"993","TN":"216","TO":"676","TR":"90","TT":"1","TV":"688","TW":"886","TZ":"255",
"UA":"380","UG":"256","US":"1","UY":"598","UZ":"998",
"VA":"379","VC":"1","VE":"58","VG":"284","VI":"340","VN":"84","VU":"678",
"WF":"681","WS":"685",
"YE":"967","YT":"262",
"ZA":"27","ZM":"260","ZW":"263"]
