All Flashcards
What does the following code output?
java
String str = "Hello";
int len = str.length();
System.out.println(len);
5
What does the following code output?
java
String str = "Peter Cao";
String sub1 = str.substring(0, 5);
System.out.println(sub1);
Peter
What does the following code output?
java
String str1 = "hello";
String str2 = "Hello";
boolean isEqual = str1.equals(str2);
System.out.println(isEqual);
false
What does the following code output?
java
String str1 = "apple";
String str2 = "banana";
int result = str1.compareTo(str2);
System.out.println(result > 0);
false
What does the following code output?
java
String s6 = "hello world";
int pos = s6.indexOf("l");
System.out.println(pos);
2
What does the following code output?
java
String s3 = "cat";
String s2 = s3.substring(1,3);
System.out.println(s2);
at
What does the following code output?
java
String s5 = "Blue";
String s6 = "Blue";
int answer = s5.compareTo(s6);
System.out.println(answer);
0
What does the following code output?
java
String str = "Coding";
String sub = str.substring(1, 4);
System.out.println(sub);
odi
What does the following code output?
java
String text = "programming";
int index = text.indexOf("m");
System.out.println(index);
7
What does the following code output?
java
String s4 = "hello";
String s2 = s4.substring(3);
System.out.println(s2);
lo
What are the differences between equals() and compareTo()?
equals() checks for content equality (boolean), compareTo() checks lexicographical order (int).
What are the differences between substring(int beginIndex, int endIndex) and substring(int beginIndex)?
The first extracts a substring between two indices, the second extracts from a start index to the end of the string.
What is a substring?
A sequence of characters within a larger string.
What is a zero-indexed language?
A language where counting starts at 0, not 1.
What does the length() method do?
Returns the number of characters in a string.
What does the substring() method do?
Returns a substring of a string.
What does the equals() method do?
Checks if two strings have the same characters in the same order (case-sensitive).
What does the compareTo() method do?
Compares two strings lexicographically (alphabetical order).
What is an external library?
A collection of pre-written code for common tasks.
What is an API?
A set of functions and procedures that allow the creation of applications which access the features or data of an operating system, application, or other service.
What is the purpose of Java documentation?
To list available methods and how to use them for a Java class, library, or API.
What is the java.lang package?
A package in Java that contains core classes; classes in this package are automatically imported.