[How to write a program to print the number of digits in an integer?]

#include <stdio.h> 
 
int nodiai(int n){ 
        int x = 0; 
        while(n){ 
                x++; 
                n /= 10; 
        } 
        return x; 
} 
 
int main(){ 
        printf("%d, %d\n", 1234, nodiai(1234)); 
        printf("%d, %d\n", 1234567, nodiai(1234567)); 
} 

 

[What is the best way to create a responsive menu using only CSS and HTML?]

 

Using media queries:

@media only screen and (min-width: 320px) and (max-width: 768px) { 
     .nav { 
         width:100%; 
    } 
     .nav-item { 
         width:100%; 
         float:none; 
    } 
} 

 

[As a Java programmer, when do you use nested interfaces?]

I have never used nested interfaces. The only case I can see where this is sensible is the multi-layered Sealed Interface pattern, e.g.

interface Event { 
    // definitions 
     
    interface Foo extends Event { 
        // Foo-specific event definitions 
    } 
 
    interface Bar extends Event { 
        // Bar-specific event definitions 
    } 
} 

 

[What is the difference between a const int and an int in the C programming language?]

The const int (or int const) cannot be modified after definition. The int can.

Example:

const int a = 2; 
int b; 
b = a; 
b++; 

 

[How do you assign a value to a pointer variable?]

int a; 
int *b = &a; 

Here the b is a pointer. It has been assigned value &a, which means the-address-of-a.

[Is it possible to find the length of a string without using the strlen() function in C programming?]

#include <stdio.h> 
#include <string.h> 
 
int main(){ 
        char s[] = {"This is a string"}; 
        printf("strlen says: %d\n", strlen(s)); 
        int i = 0; 
        do{ 
                i++; 
        }while(s[i]); 
        printf("my calculation: %d\n", i); 
} 

 

[What is the difference between (! P<q) and (p>=q) in the C programming language?]

 

After fixing a tiny error there is no difference

#include <stdio.h> 
 
int main(){ 
        int p = 3, q = 4; 
        printf("%d\n", (!(p<q))); 
        printf("%d\n", (p>=q)); 
        p = 4, q = 3; 
        printf("%d\n", (!(p<q))); 
        printf("%d\n", (p>=q)); 
} 

 

[How and when should you use the curly {}" braces in programming specifically in C++ for beginners?]

 

Curly braces are used for initialization of objects. If the object supports it the members (storage) of the object will be directly assigned to the values in the braces.

std::string s{"a string"}; 
 
int a[] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 20 }; 
 
struct X 
{ 
 int x; 
 int y; 
 int z; 
}; 
 
X x{ 1, 3, 5}; 
 
X y =  { 4, 5, 6}; 
This is called Unified Initialization, so that there is a consistent syntax, based around curly braces:

int i{};     // initialized built-in type, equals to int i{0}; 
 
int j{10};  // initialized built-in type 
 
int a[]{1, 2, 3, 4} // Aggregate initialization 
 
X x1{};    // default constructor 
 
X x2{1};   // Parameterized constructor; 
 
X x4{x3}; // copy-constructor 
 
int* arr = new int[5]{ 1, 2, 3, 4, 5 };  //dynamic allocation with initialization 

 

[How to reverse a string in C++ without a function?]

Here is how to reverse a string without a function:

#include <iostream>

#include <cstring>

using namespace std;

int main() {

int i, n = 123456789, j, k, l, strlen;

char str[10*(sizeof(char))];

char newstr[sizeof(str)];

bool is_positive = true;

k=sizeof(str)/sizeof(str[0]);

if (k < 0 ) {

is_positive = false;

}

if (k < 0 )

is_positive = false;

sprintf(str,"%d",n);

//converts to decimal base.

cout << " k is " << k << " str is " << str << endl;

if (!is_positive)

exit(1);

j = 0;

l = k-2;

i = 0;

while(i++ <= k){

/*cout << "newstr[" << j << "] is " << newstr[j]

<< " str[" << l << "] is " << str[l] << endl;

*/

newstr[j++] = str[l--];

}

cout << "newstr is " << newstr << endl;

return 0;

}

Outputs

k is 10 str is 123456789

newstr is 987654321

Without using reverse of swap functions.

 

[What is the largest heading in HTML?]

 

<h1></h1> is the largest heading tag in HTML.

But,it can be customized by CSS to make it more large.

Example :

<!DOCTYPE html> 
<html> 
<head> 
<style> 
  h1{ 
  font-size: 62px; 
  } 
</style> 
</head> 
<body> 
  <h1>The table element</h1> 
</body> 
</html> 

 

[How do you add options to a select box in JavaScript?]

Add options to a select box in JavaScript:

1) Using the Option constructor and add() method:

First, use the Option constructor to create a new option with the specified option text and value:

let newOption = new Option('Option Text','Option Value'); 
Then, call the add() method of the HTMLSelectElement element:

const select = document.querySelector('select');  
select.add(newOption,undefined); 
2) Using the DOM methods

First, construct a new option using DOM methods:

// create option using DOM 
const newOption = document.createElement('option'); 
const optionText = document.createTextNode('Option Text'); 
// set option text 
newOption.appendChild(optionText); 
// and option value 
newOption.setAttribute('value','Option Value'); 
Second, add the new option to the select element using the appendChild() method:

const select = document.querySelector('select');  
select.appendChild(newOption); 

 

[Is it possible to access elements of an array without using indexes in the C programming language?]

Sure, like this:

#include <stdio.h> 
 
int main() { 
  char *a = "Gdkkn\37vnqkc"; 
  for (int i = 0; i < strlen(a); i++)  
    printf("%c", *(a + i) + 1); 
} 

The a is an array. Its elements are accessed without indexes.

[What is a string array in C++?]

It's an array of strings. Example: #include <string> #include <iostream> #include <array> int main() { std::array<std::string, 2> a = {"Hello ", "world!"}; std::cout << a[0] << a[1]; } Here the a is an array of strings.

[What is the purpose of using two equal signs in PHP code?]

Two equal signs is a comparison.

So:

$a=1;

Sets $a to 1. Now we can use it to test.

If ($a==1)

echo ‘A equals 1’;

If (!$a!==1)

echo ‘A does not equal 1’;

You do have other ways of using this:

>= check for greater than or equal to

!>= not greater than or equal to.

And the same for lesser than.

 

[How to redirect multiple URLs using PHP?]

Assuming each URL is a .php file then set the PHP file yo:

<?php

header (‘Location: /path/to/newUrl.php');

Exit();

If you have one PHP script with different get data:

<?php

# this is index.php. you call it with

# index.php?page=1

# to

# index.php?page=4

# you should do this with case, but this works.

If ($_GET[‘page']==1)

{

header (‘Location: /path/page1.php');

exit ();

}

If ($_GET[‘page']==2)

{

header (‘Location: /path/page2.htm');

exit ();

}

If ($_GET[‘page']==3)

{

header (‘Location: /path/page3.html');

exit ();

}

If ($_GET[‘page']==4)

{

header (‘Location: https://new.domain. com');

exit ();

}

 

[What is the difference between XML and HTML tags?]

XML doesn’t tolerate syntax errors. HTML does, with specifications on to correct them.

XML tags have to be closed. They can auto-close, like <stuff/> which is equivalent to <stuff></stuff>. HTML tags that are meant to be empty, don’t need a syntax that closes them.

XML tags’ attribute values have to be quote. It’s <a thing="stuff"> or <a thing='stuff'> but not <a thing=stuff>

XML tags don’t tolerate < other than to open a tag. If you want the text < in XML you need &lt; . In HTML you can use < if it doesn’t look like a correct tag opening.

That’s just the obvious. There are many others.

[How can I create a shuffled list of integers in Python?]

Randint() and shuffle are your friends here.

import random 
test_list = [random.randint(-100000, 100000) for i in range(300)] 
print(f"300 Random Ints \n{test_list}") 
# shuffle() mixes the list in place  
second_list = list(range(40)) 
random.shuffle(second_list) 
print(f"First 40 Ints shuffled \n{second_list}") 
# sample returns a new list and leaves the old one alone 
string_list = "Tell me and I forget, teach me and I may remember, involve me and I learn.  Benjamin Franklin".split() 
shuffled_words = random.sample(string_list,len(string_list)) 
print(f"Original words \n{string_list}") 
print(f"And sample() to shuffle\n{shuffled_words}") 

The random.randint() and range() creates a list of 300 numbers selected randomly, from -100,000 to 100,000. Just change the parameters to get what you want. The second shuffles any list not just Integers. Sample() also shuffles and existing list, but creates a new list.

 

[How do you set a default value for an argument in python 3.6?]

While defining the function or class, in the parentheses (), write the parameter followed by a =, followed by the default value…

class Circle(): 
        pi = 3.14 
         
        def __init__(self, radius=2): 
                self.radius = radius 
         
        def area(self): 
                return self.pi * (self.radius)**2 
 
 
c = Circle() 
 
print(c.area()) 
#OUTPUT 
12.56 

 

[How can we ensure that the user enters only positive integers in a Python program?]

 

I would use a function But you can just put the code anywhere

def get_pos_int(prompt='Please enter a positive Integer:'): 
    while True: 
        inp = input(prompt) 
        try: 
            num = int(inp) 
        except ValueError: 
            print(f"{inp} was not an Integer") 
            continue 
        else: 
            if num < 0: 
                print(f"{num} is not a positive Integer") 
                continue 
            else: 
                break 
    return num 
 
a = 1 + get_pos_int("Please enter a number to add to one:")  
 
print(f"result was {a}") 
 
b = get_pos_int() 
print (f"got {b} back") 
Output

python get_positive.py  
Please enter a number to add to one:-12 
-12 is not a positive Integer 
Please enter a number to add to one:A 
A was not an integer 
Please enter a number to add to one:4 
result was 5 
Please enter a positive Integer:10 
got 10 back 

 

[How do you set an H1 font size (HTML, CSS, and development)?]

Code Example : <html> <head> <style> h1{ font-size: 8px; } </style> </head> <body> <h1>Changing 1st heading size by Internal CSS<h1> <h1 style=”font-size:14px;”>Changing Second heading size by Inline CSS<h1> </body> </html>

 

[How do you use a CSS calc function in an HTML element?]

The calc() CSS function lets you perform calculations when specifying CSS property values. It can be used anywhere a <length>, <frequency>, <angle>, <time>, <percentage>, <number>, or <integer> is allowed.

Example:

width: calc(100% - 80px); 
width: calc(10px + 100px); 
width: calc(100% - 30px); 
width: calc(2em * 5); 
width: calc(var(--variable-width) + 20px); 
Usage with integers:

.modal { 
  z-index: calc(3 / 2); 
} 

 

[What is the CSS code to make a button transparent?]

 

Here is the HTML & CSS code for transparent button:

<!DOCTYPE html>

<html>

<head>

<style>

button {

background-color: #65d7f521;

padding: 10px 20px;

border: none;

color: #00000091;

}

</style>

</head>

<body>

<button>Button</button>

</body>

</html>

 

[What is the best way to check if a string is valid JSON or not using JavaScript?]

 

Try to parse it and catch any failure. There isn’t a more fool-proof way to check if JSON is valid than that. Something like this would work:

function isValidJSON(s) { 
        try { 
                JSON.parse(s); 
                return true; 
        } 
        catch (e) { 
        } 
        return false; 
} 
 
// Run a few test cases: 
console.log(`isValidJSON("4") = ${isValidJSON("4")}`); // prints true 
console.log(`isValidJSON("[4") = ${isValidJSON("[4")}`); // prints false 
console.log(`isValidJSON("[4]") = ${isValidJSON("[4]")}`); // prints true 

 

[How can I create a curved line of text using CSS?]

Here is the HTML & CSS code for curved text:

<!DOCTYPE html> 
<html lang="en"> 
<head> 
    <!--Style to transform text in an arc --> 
    <style type=text/css> 
        /* Apply the translate and rotate transformation 
           for our text to look curved  */ 
        .Q { 
            transform: translate(20px, 85px) rotate(-30deg); 
        } 
        .u { 
            transform: translate(13px, 55px) rotate(-25deg); 
        } 
   
        .o { 
            transform: translate(6px, 35px) rotate(-20deg); 
        } 
   
        .r { 
            transform: translate(3px, 23px) rotate(-15deg); 
        } 
   
        .a { 
            transform: translate(2px, 14px) rotate(-10deg); 
        } 
        .A { 
            transform: translate(1px, 8px) rotate(-5deg); 
        } 
        .n { 
            transform: translate(0px, 5px) rotate(0deg); 
        } 
        .s { 
            transform: translate(-1px, 8px) rotate(5deg); 
        } 
        .w { 
            transform: translate(-2px, 14px) rotate(10deg); 
        } 
        .e { 
            transform: translate(-3px, 25px) rotate(15deg); 
        } 
        .e { 
            transform: translate(-6px, 30px) rotate(20deg); 
        } 
        .r1 { 
            transform: translate(-14px, 50px) rotate(25deg); 
        } 
        .s1 { 
            transform: translate(-24px, 68px) rotate(29deg); 
        } 
   
        /* An inline-block element is placed as an inline 
         element (on the same line as adjacent content),  
         but it behaves like a block element  */ 
   
        span { 
            display: inline-block; 
        } 
    </style> 
</head> 
   
<body> 
    <div style="text-align: center; padding-top: 250px; 
                font-size: 55px; color: green;"> 
   
        <!-- Declare all the characters of text  
            one-by-one, inside span tags --> 
        <span class="Q">Q</span> 
        <span class="u">u</span> 
        <span class="o">o</span> 
        <span class="r">r</span> 
        <span class="a">a</span> 
        <span class="A">A</span> 
        <span class="n">n</span> 
        <span class="s">s</span> 
        <span class="w">w</span> 
        <span class="e">e</span> 
        <span class="r1">r</span> 
        <span class="s1">s</span> 
    </div> 
</body> 
</html> 

 

[How do you add a link to an image using HTML and CSS?]

<img src=”NameOfThePic”> If it's in a different folder it's the same but with <img src=“FolderName/NameOfPic”>