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Numbers and Strings
Questions and Exercises: Characters and Strings
Questions
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What is the initial capacity of the following string builder?
StringBuilder sb = new StringBuilder("Able was I ere I saw Elba.");
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Consider the following string:
String hannah = "Did Hannah see bees? Hannah did.";
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What is the value displayed by the expression
hannah.length()
?
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What is the value returned by the method call
hannah.charAt(12)
?
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Write an expression that refers to the letter
b
in the string
referred to by hannah
.
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How long is the string returned by the following expression?
What is the string?
"Was it a car or a cat I saw?".substring(9, 12)
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In the following program,
called
ComputeResult
, what is the value of result
after each numbered line executes?
public class ComputeResult {
public static void main(String[] args) {
String original = "software";
StringBuilder result = new StringBuilder("hi");
int index = original.indexOf('a');
/*1*/ result.setCharAt(0, original.charAt(0));
/*2*/ result.setCharAt(1, original.charAt(original.length()-1));
/*3*/ result.insert(1, original.charAt(4));
/*4*/ result.append(original.substring(1,4));
/*5*/ result.insert(3, (original.substring(index, index+2) + " "));
System.out.println(result);
}
}
Exercises
-
Show two ways to concatenate the following two strings
together to get the string
"Hi, mom."
:
String hi = "Hi, ";
String mom = "mom.";
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Write a program that computes your initials from your full name and
displays them.
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An anagram is a word or a phrase made by transposing the letters of
another word or phrase; for example, "parliament" is an anagram of
"partial men," and "software" is an anagram of "swear oft." Write a
program that figures out whether one string is an anagram of another
string. The program should ignore white space and punctuation.
Check your answers.