I need to check if a string is composed by 3 capital letters and 4 digits.
For example: ABC1234
OBS: Without using regular expressions?
This is what I have tried so far. Thanks!
public static void main(String[] args) {
String input = "ABC1234";
String firstThreeChars = ""; //substring containing first three characters
String lastFourChars = ""; //substring containing last four characters
if (input.length() > 4) {
firstThreeChars = input.substring(0, 3);
}
if (input.length() > 4) {
lastFourChars = input.substring(input.length() - 4);
}
System.out.println(firstThreeChars);
System.out.println(lastFourChars);
}
I'm guessing that the letters and numbers are in random places in the string.
if (input.length != 7) { System.out.println("No"); return; } int letterCount = 0, digitCount = 0; for (int i = 0; i < 7; ++i) { char c = input.charAt(i); if (c >= 'A' && c <= 'Z') { ++letterCount; } else if (c >= '0' && c <= '9') { ++digitCount; } else { System.out.println("No"); return; } } if (letterCount == 3 && digitCount == 4) { System.out.println("Yes"); } else { System.out.println("No"); }
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