Menu
How do you check how many letters are in a Java string?
How do you check what letter is in a certain position in the string (i.e, the second letter of the string)?
640
String str = "9as78"; Now loop through the length of this string and use the Character. isLetter() method. Within that, use the charAt() method to check for each character/ number in the string.
String length limit: The maximum length a string can have is: 231-1.
Let's start with a simple/naive approach: String someString = "elephant"; char someChar = 'e'; int count = 0; for (int i = 0; i < someString. length(); i++) { if (someString. charAt(i) == someChar) { count++; } } assertEquals(2, count);
A)
String str = "a string"; int length = str.length( ); // length == 8 http://download.oracle.com/javase/7/docs/api/java/lang/String.html#length%28%29
edit
If you want to count the number of a specific type of characters in a String, then a simple method is to iterate through the String checking each index against your test case.
int charCount = 0; char temp; for( int i = 0; i < str.length( ); i++ ) { temp = str.charAt( i ); if( temp.TestCase ) charCount++; } where TestCase can be isLetter( ), isDigit( ), etc.
Or if you just want to count everything but spaces, then do a check in the if like temp != ' '
B)
String str = "a string"; char atPos0 = str.charAt( 0 ); // atPos0 == 'a' http://download.oracle.com/javase/7/docs/api/java/lang/String.html#charAt%28int%29
103
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
