C Sc 127A Monday 10-Nov Scribe's Section Leader ___________
Collaboration Work in teams of 2. The scribe is the person born closest to this room. Write the
scribe's section leader above and both names below:
1. _______________________________ 2. __________________________________
Problem Add method substring to class String127A to return a new java.lang.String like that String
class already does. Assume the indexes are in range and the 1st int argument <= 2nd int argument.
These assertions must pass
String127A str = new String127A("abcd");
assertEquals("", str.substring(1, 1)); // empty string
assertEquals("a", str.substring(0, 1));
assertEquals("abc", str.substring(0, 3));
assertEquals("abcd", str.substring(0, 4));
assertEquals("bcd", str.substring(1, 4));
assertEquals("cd", str.substring(2, 4));
assertEquals("d", str.substring(3, 4));
assertEquals("", str.substring(4, 4));
// A mutable string type
public class String127A {
private int n;
private char[] theChars;
// Precondition: initialString.length() <= 128
public String127A(String initialString) {
theChars = new char[128];
n = initialString.length();
for (int i = 0; i < n; i++)
theChars[i] = initialString.charAt(i);
}
public int length() {
return n;
}
// Precondition: index is in range of 0..size() - 1
public char charAt(int index) {
return theChars[index];
}
// Preconditions: beginIndex is in range of 0..size()
// endIndex is in range of 0..size()
// beginIndex <= endIndex
public String substring(int beginIndex, int endIndex) {
