Javascript Convert String To Integer

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Programmers use different types of data to store different types of values. For example, they use strings to store text- based data and integers to store integers.

When the code is written, you may decide to convert the data type from one value to another data type. One of the most common type conversions done in Java is converting a string to an integer. This is where the parseInt () and () valueOf methods come into play .

You can use the Java parseInt () and valueOf () methods to convert a string to an integer. In this tutorial we will discuss, with examples, how to do this.

Java data types

Java, like any other programming language, uses different data types to classify the types of data that contains a value. True / false values, for example, are stored as Booleans and text is stored as a string.

This is an important feature in programming because the type of a data value will determine how that value can be manipulated. For example, you can perform mathematical operations on whole and real numbers, but not on strings.

While programming, you may come across a situation where you need to convert an entire string. For example, if you want to perform a mathematical operation on a number stored as a string, you will need to convert the data value type

Java String to Integer. ParseInt using ()

You can use the parseInt () method to perform a string to integer conversion in Java. parseInt () takes one parameter: the string value you want to convert to an integer

The syntax for parseInt () looks like this:.

Integer.parseInt (value);

Suppose you write a program for a theme park that checks the age of a guest when entering some di attractions. is stored as a string, but we want to convert it to an integer so that we can compare it to the appropriate minimum age we could convert the customer’s age (15 in this example) to an integer using this code: .

Our code returns:

the age of this customer is: 15

Descended break our code In the first line of our. ConvertAge, we declare a string - method which stores our customer’s age

Then we use the parseInt () at - called age. parse the value of the string and convert it to an integer. We assign the new integer value to integer_age variable. Finally, we print a message saying: "the age of this customer is:", followed by the age of the customer

We can check the type of our data using the keyword instanceof . Returns instanceof a Boolean value (true or false) depending on whether the value we are checking contains a particular type of data. The following code, added at the end of our previous program, allows us to verify that integer_age is an integer:


System. on .println ("age is an integer?" + age instanceof integer);


Our code returns:

The age of this customer is: 15

Age is an integer? true

In our code, we use the age instanceof integer to check if the variable age is an integer. age is an integer, so the return keyword instanceof: true

Java string to integer: use valueOf ()

You can also use the valueOf () method to convert a string to an integer in Java. valueOf () takes one parameter: the value you want to convert to an integer

Here is the syntax for the valueOf (): method.

Integer .valueOf (value);

Let’s take an example to illustrate how the valueOf () method works. Suppose you write a program that stores the quantities of Colombian roasted coffee and Italian beans sold in a coffee store. Our program currently stores these quantities as a string, but we want to convert them to integers. We could use the following code to do this:

Our code returns:

Quantity of beans Colombian coffee: 15

Quantity of roasted Italian coffee: 19

Descended break our code. On the first line of our ConvertQuantities class, we declare a variable called and Columbian assign it the value 15. Then we declare a variable italian_roast and assign it the value 19.

Then we use the m valueOf () method to convert the value of Columbian to an integer and assign that integer to columbian_integer variable.

We also use valueOf () to convert the value of italian_roast to assign an integer and that integer value to the italian_roast_integer variable.

Next, we print the quantities of the two beans, using the integer values ‚Äã‚Äãof each kernel.


There are two ways to convert a string to an integer in Java: the parseInt () method and the valueOf () method. This tutorial has discussed databases of data types in Java and how you can use both methods to convert a string to an integer. We have also shown an example of each method in the

Now that you have the knowledge to convert strings to integers in Java as a! pro

Javascript Convert String To Integer iat: Questions


InsecurePlatformWarning: A true SSLContext object is not available. This prevents urllib3 from configuring SSL appropriately

3 answers

Tried to perform REST GET through python requests with the following code and I got error.

Code snip:

import requests
header = {"Authorization": "Bearer..."}
url = az_base_url + az_subscription_id + "/resourcegroups/Default-Networking/resources?" + az_api_version
r = requests.get(url, headers=header)


          InsecurePlatformWarning: A true SSLContext object is not available. 
          This prevents urllib3 from configuring SSL appropriately and may cause certain SSL connections to fail. 
          For more information, see

My python version is 2.7.3. I tried to install urllib3 and requests[security] as some other thread suggests, I still got the same error.

Wonder if anyone can provide some tips?


Answer #1

The docs give a fair indicator of what"s required., however requests allow us to skip a few steps:

You only need to install the security package extras (thanks @admdrew for pointing it out)

$ pip install requests[security]

or, install them directly:

$ pip install pyopenssl ndg-httpsclient pyasn1

Requests will then automatically inject pyopenssl into urllib3

If you"re on ubuntu, you may run into trouble installing pyopenssl, you"ll need these dependencies:

$ apt-get install libffi-dev libssl-dev


Dynamic instantiation from string name of a class in dynamically imported module?

3 answers

In python, I have to instantiate certain class, knowing its name in a string, but this class "lives" in a dynamically imported module. An example follows:

loader-class script:

import sys
class loader:
  def __init__(self, module_name, class_name): # both args are strings
      modul = sys.modules[module_name]
      instance = modul.class_name() # obviously this doesn"t works, here is my main problem!
    except ImportError:
       # manage import error

some-dynamically-loaded-module script:

class myName:
  # etc...

I use this arrangement to make any dynamically-loaded-module to be used by the loader-class following certain predefined behaviours in the dyn-loaded-modules...


Answer #1

You can use getattr

getattr(module, class_name)

to access the class. More complete code:

module = __import__(module_name)
class_ = getattr(module, class_name)
instance = class_()

As mentioned below, we may use importlib

import importlib
module = importlib.import_module(module_name)
class_ = getattr(module, class_name)
instance = class_()


How to get all of the immediate subdirectories in Python

3 answers

I"m trying to write a simple Python script that will copy a index.tpl to index.html in all of the subdirectories (with a few exceptions).

I"m getting bogged down by trying to get the list of subdirectories.


Answer #1

import os
def get_immediate_subdirectories(a_dir):
    return [name for name in os.listdir(a_dir)
            if os.path.isdir(os.path.join(a_dir, name))]

Javascript Convert String To Integer JavaScript: Questions

JSON datetime between Python and JavaScript

4 answers

kevin By kevin

I want to send a datetime.datetime object in serialized form from Python using JSON and de-serialize in JavaScript using JSON. What is the best way to do this?


Answer #1

You can add the "default" parameter to json.dumps to handle this:

date_handler = lambda obj: (
    if isinstance(obj, (datetime.datetime,
    else None
json.dumps(, default=date_handler)

Which is ISO 8601 format.

A more comprehensive default handler function:

def handler(obj):
    if hasattr(obj, "isoformat"):
        return obj.isoformat()
    elif isinstance(obj, ...):
        return ...
        raise TypeError, "Object of type %s with value of %s is not JSON serializable" % (type(obj), repr(obj))

Update: Added output of type as well as value.
Update: Also handle date

What blocks Ruby, Python to get Javascript V8 speed?

4 answers

Are there any Ruby / Python features that are blocking implementation of optimizations (e.g. inline caching) V8 engine has?

Python is co-developed by Google guys so it shouldn"t be blocked by software patents.

Or this is rather matter of resources put into the V8 project by Google.


Answer #1

What blocks Ruby, Python to get Javascript V8 speed?


Well, okay: money. (And time, people, resources, but if you have money, you can buy those.)

V8 has a team of brilliant, highly-specialized, highly-experienced (and thus highly-paid) engineers working on it, that have decades of experience (I"m talking individually – collectively it"s more like centuries) in creating high-performance execution engines for dynamic OO languages. They are basically the same people who also created the Sun HotSpot JVM (among many others).

Lars Bak, the lead developer, has been literally working on VMs for 25 years (and all of those VMs have lead up to V8), which is basically his entire (professional) life. Some of the people writing Ruby VMs aren"t even 25 years old.

Are there any Ruby / Python features that are blocking implementation of optimizations (e.g. inline caching) V8 engine has?

Given that at least IronRuby, JRuby, MagLev, MacRuby and Rubinius have either monomorphic (IronRuby) or polymorphic inline caching, the answer is obviously no.

Modern Ruby implementations already do a great deal of optimizations. For example, for certain operations, Rubinius"s Hash class is faster than YARV"s. Now, this doesn"t sound terribly exciting until you realize that Rubinius"s Hash class is implemented in 100% pure Ruby, while YARV"s is implemented in 100% hand-optimized C.

So, at least in some cases, Rubinius can generate better code than GCC!

Or this is rather matter of resources put into the V8 project by Google.

Yes. Not just Google. The lineage of V8"s source code is 25 years old now. The people who are working on V8 also created the Self VM (to this day one of the fastest dynamic OO language execution engines ever created), the Animorphic Smalltalk VM (to this day one of the fastest Smalltalk execution engines ever created), the HotSpot JVM (the fastest JVM ever created, probably the fastest VM period) and OOVM (one of the most efficient Smalltalk VMs ever created).

In fact, Lars Bak, the lead developer of V8, worked on every single one of those, plus a few others.

Django Template Variables and Javascript

4 answers

When I render a page using the Django template renderer, I can pass in a dictionary variable containing various values to manipulate them in the page using {{ myVar }}.

Is there a way to access the same variable in Javascript (perhaps using the DOM, I don"t know how Django makes the variables accessible)? I want to be able to lookup details using an AJAX lookup based on the values contained in the variables passed in.


Answer #1

The {{variable}} is substituted directly into the HTML. Do a view source; it isn"t a "variable" or anything like it. It"s just rendered text.

Having said that, you can put this kind of substitution into your JavaScript.

<script type="text/javascript"> 
   var a = "{{someDjangoVariable}}";

This gives you "dynamic" javascript.


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