In Java, the substring method is used to extract a portion of a given string. This method can be used to extract a single character, a subsequence of characters or a substring. The substring method can be used with two different parameters, which determine the beginning and end positions of the substring.
Syntax of substring method in Java:
public String substring(int beginIndex)
public String substring(int beginIndex, int endIndex)
In the first syntax, the substring method is used to extract a portion of the string from beginIndex to the end of the string. In the second syntax, the substring method is used to extract a portion of the string from beginIndex to endIndex-1.
Code Example 1:
String str = "Hello World";
String name = str.substring(6);
System.out.println(name);
Output: World
In this example, the variable str contains the string "Hello World". We use the substring method to extract the substring from index 6 to the end of the string. We assign this substring to the variable name and print it. The output of this program will be "World".
Code Example 2:
String str2 = "Hello World";
String name2 = str2.substring(0, 5);
System.out.println(name2);
Output: Hello
In this example, the variable str2 contains the string "Hello World". We use the substring method to extract the substring from index 0 to index 5 (the character at index 5 is not included in the substring). We assign this substring to the variable name2 and print it. The output of this program will be "Hello".
Code Example 3:
String str3 = "Techie Achievers";
String name3 = str3.substring(0, 6);
System.out.println("Substring: " + name3);
Output: Substring: Techie
In this example, the variable str3 contains the string "Techie Achievers". We use the substring method to extract the substring from index 0 to index 5 and assign it to the variable name3. We print the value of name3 using the System.out.println() method. The output of this program will be "Substring: Techie".
Code Example 4:
String str4 = "Techie Achievers";
String name4 = str4.substring(7, 16);
System.out.println("Substring: " + name4);
Output: Substring: Achievers
In this example, the variable str4 contains the string "Techie Achievers". We use the substring method to extract the substring from index 7 to index 15 (the character at index 15 is not included in the substring). We assign this substring to the variable name4 and print it. The output of this program will be "Substring: Achievers".
In conclusion, the substring method is a very useful method in Java for extracting substrings from a given string. It is used to extract a subsequence of characters from a string starting at a given index and ending at another index. The substring method can be used in many different situations and is very versatile.
here are more details about the previous topics:
- For loops:
The for loop in Java is a control flow statement that is used to iterate over a block of code a certain number of times. It is used when the number of iterations is known beforehand. The general syntax of a for loop is as follows:
for(initialization; condition; increment/decrement) {
//statement(s)
}
The initialization statement is executed only once at the beginning of the loop. This statement is used to declare and initialize any variables that will be used in the loop. The condition statement is evaluated at the beginning of each iteration and determines whether the loop should continue or not. The increment/decrement statement is executed at the end of each iteration and is used to update the condition statement.
- If-else statements:
The if-else statement in Java is used to execute a block of code if a specified condition is true. If the condition is false, then a different block of code can be executed. The general syntax of if-else statement is as follows:
if(condition) {
//statement(s) if condition is true
} else {
//statement(s) if condition is false
}
The if statement is evaluated and if it is true, the code within the if block is executed. If it is false, the code within the else block is executed. If-else statements can also be nested to provide more complex branching.
- While loops:
The while loop in Java is a control flow statement that is used to execute a block of code repeatedly as long as a certain condition is true. The general syntax of a while loop is as follows:
while(condition) {
//statement(s)
}
The condition is evaluated at the beginning of each iteration and if it is true, then the code within the loop is executed. If it is false, then the loop exits and the program continues to execute the code following the while loop.
- Switch case statements:
The switch statement in Java is used to select one of many blocks of code to be executed. It compares the value of a variable against multiple cases until a match is found. The general syntax of switch statement is as follows:
switch(variable){
case value1:
//statement(s)
break;
case value2:
//statement(s)
break;
…
default:
//statement(s) if none of the cases is matched
}
The switch statement compares the variable against each case value until a match is found. If a match is found, the code within the matching case is executed. The default block is executed if none of the case values matches the variable.
Popular questions
-
What is the purpose of the substring method in Java?
Answer: The substring method in Java is used to extract a portion of a given string. It can be used to extract a single character, a subsequence of characters or a substring. -
Can the substring method be used to extract a subsequence of characters from a string?
Answer: Yes, the substring method can be used to extract a subsequence of characters from a string. -
What is the syntax of the substring method in Java?
Answer: The substring method in Java has two different parameters:
- public String substring(int beginIndex)
- public String substring(int beginIndex, int endIndex)
-
What happens if the endIndex parameter of the substring method is not provided?
Answer: If the endIndex parameter is not provided, then the substring method extracts the substring from beginIndex to the end of the string. -
Can the substring method be used with negative index values?
Answer: No, the substring method cannot be used with negative index values. It will throw an IndexOutOfBoundsException if the beginIndex parameter is negative or greater than the length of the given string.
Tag
"Substring"
