Behaviour of Printf
1. if '' or "" are not used the behaviour of printf becomes to be print and echo
Important Interview Question based on - escape Operator
1.How will you print \ using printf
printf("\\")
2.What does escape operator internally do ?
a -> plain Operator
% -> convertible string or operator
\-> convertible string
"=> print as it is
\ escape operator converts convertible string to plain string
3. How to print \n inside printf()
using \\n as \ as escape operator
4. How to print %d inside printf()
Answer : behaviour of escape operator(\,%) can only be changed by its operator
itself
5. How to print % inside printf()
use %% to escape suffix %
6. Can you a special operator will cannot be escape by \
% modulo operator
2. can you tell a special digit which cannot escape by \
\0 => NULL
Some of the Important escape character sequence
\a => alarm,beep
\f => form feed
\b => backspace
\v => verticle tab
\t => horizontal tab
\n => new line
\r => return carriage
Format Specifiers
1. %d - Interger
printf("The no is %d")
|--------->convertible string
Argument List [<...>] : is the no of supplied argument seperated by comma,s in any function as single argument entity.
for example
printf([arg1],[arg2,arg3,arg4,arg5...]); valid
|1 1 2 3 4 |
|2
printf([arg1],[arg2],[arg3],[arg4],[arg5]); invalid
|1 |2 |3 |4 |5
Total No of Argument = 5
Total No of Entity =5
Example:
$a=10;
$b=20;
add($a,$b);
total no of arguemnt =2
total no of Entity =2
$a=10;
$b=[10,20,30,40,50,60...]
add($a,$b);
Q1 :
print_r([arg1],[arg2]);
printf([arg1],[arg2,arg3,arg4,arg5]);
printf([arg1],[arg2]);
In java
public static void main(String arg[])
public static void main(String arg...)
Most Common Error while using format specifier
few Argument supplied Count Error
if you using min 1 format specifier and not supplying argument list
too few argument supplied Error will raise.
character datatype =
1 .gettype() => string
2. strlen() => length in digit
if length == 1 it is character
else
it is string
This can be using ord() function
Sprintf() : it same as printf but it donot print anything rather it returns
$x=sprintf("This is no value = %d",10);
echo $x;
This is no value = 10
Difference b/w printf and sprintf
$a=sprintf("vakue=%d",10); //Output generated by print assignd as output string
$b=printf("vakue=%d",10); //no of character display on the screen
php > printf("This is no value = %d",10);
This is no value = 10
php > sprintf("This is no value = %d",10);
php > $x=sprintf("This is no value = %d",10);
php > echo $x;
This is no value = 10
php > $x=printf(10);
10
php > echo $x;
2
php > $x=printf(1000000);
1000000
php > echo $x;
7
7
php > $x=printf("awnish");
awnish
php > echo $x;
6
php > $y=printf(10);
10
php > echo $y;
2
php > $y=printf(printf("awnish"));
awnish6
php > echo $y;
1
php > $x=print(1000);
1000
php > echo $x;
1
php >
Write a program to take name as input from the user
and find the length of name
Trick: printf() returns no of character printed on the screen
echo "The length of string ";
$length=printf("%s",$name);
echo "={$length}";
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