logo
down
shadow

Why is this loop changed?


Why is this loop changed?

By : Farid
Date : October 28 2020, 08:00 PM
I wish this help you In this situation changing while() to for() is not an optimization. There is simply no way to know from bytecode which one was used in a source code.
There are many situations when:
code :
while(x)
for(;x;)
public class While{
    public static void main(String args[]) {
        int i = 0;
        while(i<5){
            System.out.println(i);
            i++;
        }
    }
}
public class For{
    public static void main(String args[]) {
        int i = 0;
        for(; i<5 ;){
            System.out.println(i);
            i++;
        }
    }
}
public class For2{
    public static void main(String args[]) {
        for(int i=0;i<5;i++){
            System.out.println(i);
        }
    }
}
public class While {
  public While();
    Code:
       0: aload_0
       1: invokespecial #1                  // Method java/lang/Object."<init>":()V
       4: return

  public static void main(java.lang.String[]);
    Code:
       0: iconst_0
       1: istore_1
       2: iload_1
       3: iconst_5
       4: if_icmpge     20
       7: getstatic     #2                  // Field java/lang/System.out:Ljava/io/PrintStream;
      10: iload_1
      11: invokevirtual #3                  // Method java/io/PrintStream.println:(I)V
      14: iinc          1, 1
      17: goto          2
      20: return
}
public class For {
  public For();
    Code:
       0: aload_0
       1: invokespecial #1                  // Method java/lang/Object."<init>":()V
       4: return

  public static void main(java.lang.String[]);
    Code:
       0: iconst_0
       1: istore_1
       2: iload_1
       3: iconst_5
       4: if_icmpge     20
       7: getstatic     #2                  // Field java/lang/System.out:Ljava/io/PrintStream;
      10: iload_1
      11: invokevirtual #3                  // Method java/io/PrintStream.println:(I)V
      14: iinc          1, 1
      17: goto          2
      20: return
}
public class For2 extends java.lang.Object{
public For2();
  Code:
   0:   aload_0
   1:   invokespecial   #1; //Method java/lang/Object."<init>":()V
   4:   return

public static void main(java.lang.String[]);
  Code:
   0:   iconst_0
   1:   istore_1
   2:   iload_1
   3:   iconst_5
   4:   if_icmpge       20
   7:   getstatic       #2; //Field java/lang/System.out:Ljava/io/PrintStream;
   10:  iload_1
   11:  invokevirtual   #3; //Method java/io/PrintStream.println:(I)V
   14:  iinc    1, 1
   17:  goto    2
   20:  return

}


Share : facebook icon twitter icon
Python loop over iterator of list whose length is changed during the loop

Python loop over iterator of list whose length is changed during the loop


By : user3247299
Date : March 29 2020, 07:55 AM
it helps some times Firstly, from you description I think you want del l[i+1] and not del l[i]
It seems to me that you code does work, I think len(l) is being update on each pass as my example is able to stop when we want it to:
code :
l = range(20)
i = 0
while i < len(l):
    print i, len(l), l
    if l[i] % 3 == 0:
        l[i] = -l[i+1]
        del l[i+1]
    else:
        i += 1
l = range(20)
i = 0
while i < len(l):
    print i, len(l), l
    if True:
        l[i] = -l[i+1]
        del l[i+1]
    else:
        i += 1
i = 0
while i + 1 < len(l): 
    if condition(l[i],l[i+1]):
        l[i] = update(l[i+1])
        del l[i+1]
    else:
        i += 1
Alternative for Swift C-style loop when iterator was changed conditionally within the loop

Alternative for Swift C-style loop when iterator was changed conditionally within the loop


By : Chaitanya Kulkarni
Date : March 29 2020, 07:55 AM
will help you The iterator variable declared in a for loop is scoped to a single pass through that loop, so if you want to change it across multiple passes through the loop you'll need to use a while loop instead.
Also, since your intention seems to be "increment the loop counter only if checkCondition() is false" you can do that more clearly with a single, conditional increment, instead of using a decrement to undo your increment. Here are a couple of examples of that:
code :
var i = 1
while i <= 10 {
    if !checkCondition() {
        i += 1
    }
}

var j = 1
while j <= 10 {
    j = checkCondition() ? j : j + 1
}
extension IntegerType {
    mutating func incrementIf(@autoclosure condition: () -> Bool) {
        if condition() {
            self = self + 1
        }
    }
}
var k = 1
while k <= 10 {
    k.incrementIf(!checkCondition())
}
for item in collection {
    process(item)
    if item.needsMoreProcessing {
        process(item) // some more
    }
}

for item in collection {
    while item.needsProcessing {
        process(item)
    }
}
why a for loop skip the first element after the list in the for loop has been changed?

why a for loop skip the first element after the list in the for loop has been changed?


By : rav_prab
Date : March 29 2020, 07:55 AM
With these it helps Don't modify a list while you are iterating over it (more information here).
Instead, try filtering the list all at once:
code :
s = [x for x in s if x[-1] != '0']
Task.Run loop with external parameters are changed by loop

Task.Run loop with external parameters are changed by loop


By : user2703287
Date : March 29 2020, 07:55 AM
To fix the issue you can do I have a suggestion for an alternative implementation, that you may or may not find suitable for your needs. Instead of processing the tasks in batches of 100 you could express the nested-for loops as a single enumerable, and then feed it to the build-in method Parallel.ForEach to do the work of parallelism.
code :
private IEnumerable<(int, int)> GetNestedFor()
{
    for (int x = 0; x < 1000; x++)
    {
        for (int y = 0; y < 1000; y++)
        {
            yield return (x, y); // return a ValueTuple<int, int>
        }
    }
}

ThreadPool.SetMinThreads(100, 100);
var options = new ParallelOptions() { MaxDegreeOfParallelism = 100 };
Parallel.ForEach(GetNestedFor(), options, item =>
{
    int param1 = item.Item1;
    int param2 = item.Item2;
    Console.WriteLine($"Processing ({param1}, {param2})");
    Thread.Sleep(100); // Simulate some work
});
How to show that a loop control variable is not changed inside the C++ for-loop body?

How to show that a loop control variable is not changed inside the C++ for-loop body?


By : Maynard John Si
Date : March 29 2020, 07:55 AM
Hope this helps I don't think this is possible for hand-crafted loop, but I'd guess that could be considered an additional argument to encourage the use of std::for_each and BOOST_FOREACH for iterations over STL container.
EDIT ... and the C++0x range-based for-loop (thanks Matthieu. M :)
Related Posts Related Posts :
  • Is O(N!*N) an acceptable big oh complexity class or do I remove the constant and just say O(N!)?
  • Java File URI error?
  • Using an interface as a constructor parameter in Java?
  • Add additional path to exec-maven-plugin
  • Natural Language parsing of an appointment?
  • Java: How to tell which fontconfig file my system is currently using?
  • How to create notification icon badge on Android apps (like iPhone)
  • Interfaces with hibernate annotations
  • Getting ConnectionTimeoutException with the host did not accept the connection within timeout
  • How to get all property names of a Groovy class?
  • Java Netscape LDAP Remove One Attribute
  • A simple two column layout with Swing
  • Making a Linked list using Generics
  • how to handle result set data
  • Cloning java ArrayList and preventing it from modifications
  • Java How to call method of grand parents?
  • running jython bytecode using java
  • get content from website with utf8 format
  • Sendgrid v3: "Substitutions may not be used with dynamic templating"
  • Application freezes when running method
  • Maven versioning using git branches
  • does a Java getter incur a performance penalty
  • Open Source Implementation of Checkers
  • How can I make a resizable array in Java?
  • Change size of ImageIcon in a JRadioButton
  • Java memory mapped files and swap
  • JAXB Annotated class - setting of a variable which is not an element
  • JSF don't find component in view root with the form id
  • Using Mockito, how do I match against the key-value pair of a map?
  • How do I run my application as superuser from Eclipse?
  • Spring-Security: Call method after authentication
  • How can I add a password to this JDBC:ODBC connection string that is trying to connect to an MS Access database
  • java.sql.SQLException: database locked
  • Json Jackson deserialization without inner classes
  • Error starting modern compiler
  • Generate a random number in interval [0,360) which is divisible by number 15
  • Rotate watermark text at 45 degree angle across the center Apache PDFBox
  • Generate Random number in a range with no repeatation
  • Starting HBASE, java.lang.ClassNotFoundException: org.apache.htrace.SamplerBuilder
  • Using getter and setter methods inside a class in my main class
  • java: <identifier> expected with ArrayList
  • Java Reflection, java.lang.IllegalAccessException Error
  • Looking for a lightweight java-compatible in-memory key-value store
  • What is your development checklist for Java low-latency application?
  • Read a line in java and then tokenize it
  • How to format a date using Apache Derby?
  • Explicitly multiplying values as longs
  • Starting out NLP - Python + large data set
  • Software Testing Tools - for java
  • JDBC transaction dead-lock: solution required?
  • Measuring the time to create and destroy a simple object
  • Javadoc error: "option --boot-class-path not allowed with target 11"
  • How can I store values in a hashmap with <String, List<Integer>>
  • JDBC ODBC.. (Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException)
  • Unable to detect Capture Device (webcam) through JMF
  • Audio fingerprinting library (java)
  • Help matching fields between two classes
  • Access variables between nested JSP tags
  • AES Encryption Java Invalid Key length
  • How to initiate chatting between two clients and two clients only, using applets and servlets?
  • shadow
    Privacy Policy - Terms - Contact Us © 35dp-dentalpractice.co.uk