Very Short
Answer
1. What is variable?
Variable is a container for store
data. It starts with a dollar sign $ and can store strings, numbers, or arrays.
2. Define constants in PHP?
Constants are like variables, but
once defined, their value cannot change. In PHP, they are defined using
define() function and do not begin with a $.
3. Discuss unary and binary
operators?
Unary operators act on a single
operand (e.g., ++$x), while binary operators require two operands (e.g., $a +
$b). They are used in arithmetic and logic.
4. Discuss break and
continue statements?
break immediately terminates the
loop, while continue skips the current iteration and proceeds with the next
one.. Both are used for flow control in loops.
5. What is an array?
An array is a data structure that stores multiple values in
one variable. It can be indexed, associative, or multidimensional in PHP.
Short Answer
1. Explain scope of
variables?
Scope defines where a variable is
accessible in PHP. There are three types: global (used outside functions),
local (inside functions), and static (retains value after function ends). Scope
affects variable behavior and visibility.
2. Explain conditional
assignment operators? Conditional assignment operators assign values based
on a condition. The ternary operator ? : is commonly used, like $x = ($a >
$b) ? $a : $b;. It’s a compact if-else form.
3. What is difference
between while and do while loop?
In while, the condition is checked
first; loop may not run if false. In do-while, the loop runs at least once
since condition is checked after execution.
4. Explain foreach loop?
foreach loop is used to iterate over arrays. It automatically assigns each
array value to a variable. Syntax: foreach($array as $value) { //code }. It
simplifies array handling.
5. What is an index array?
Indexed arrays store elements with
numeric indexes starting from 0. Example: $arr = array("apple",
"banana");. Elements are accessed using their numeric positions in
the array.
6. What is associative
array?
Associative arrays use names (keys) instead of numbers to
identify elements.Example: $arr = array("name" =>
"John", "age" => 25);. Keys act as identifiers for
values.
Long Answer
1.
Explain different data types in PHP? PHP supports several data
types:
1. Integer – Whole
numbers like 1, -100.
2. Float (Double) –
Decimal numbers like 3.14. 3. String
– Sequence of characters like "Hello".
4. Boolean – True or
False values.
5. Array – A collection
of values.
6. Object – Instances of
classes.
7. NULL – Represents a
variable with no value.
8. Resource – Special
variables referencing external resources (e.g., file handles, database
connections).
Each data type helps PHP handle
various operations efficiently. Strings can be manipulated using functions,
integers and floats are used in arithmetic, and arrays can store multiple
related values. Type juggling in PHP allows automatic type conversion when
needed, making it flexible but requiring careful handling in complex logic.
2.
Describe various types of operators in PHP? Operators in PHP
include:
1. Arithmetic Operators –
+, -, *, /, % for math.
2. Assignment Operators –
=, +=, -=, etc.
3. Comparison Operators –
==, ===, !=, <, >.
4. Logical Operators –
&&, ||, ! for logical conditions.
5. Increment/Decrement
Operators – ++, --.
6. String Operators – .
for concatenation.
7. Array Operators – +,
==, === for array comparison.
8. Conditional (Ternary)
Operator – ?: for shorthand if-else.
Operators make coding and logic
processing easier.
3.
Explain switch statement with an example?
A switch statement checks a variable's value
and runs the code block that matches a corresponding case.. It prevents long
if-else chains.
Example:
$day = "Monday"; switch ($day)
{ case "Monday":
echo "Start of the week.";
break; case "Friday":
echo "Weekend is near.";
break; default:
echo "Midweek day.";
}
The break stops execution after a
match. If no case matches, default runs.
4.
Explain different types of loop in PHP? PHP has four types of
loops:
1. while loop – Executes
while a condition is true.
2. do-while loop –
Executes at least once, then checks condition.
3. for loop – Best for
loops with counters.
4. foreach loop – Ideal
for iterating arrays.
Each loop helps reduce code
repetition and simplifies automation. Choosing the right loop depends on the
problem, like foreach for arrays and for for numeric iterations.
5.
Discuss various array functions in detail? PHP provides many
built-in array functions:
•
array_push() – Adds
elements to the end.
•
array_pop() – Removes the
last element.
•
array_merge() – Merges two
arrays.
•
array_keys() – Returns all
keys.
•
array_values() – Returns
all values.
•
in_array() – Checks if a
value exists.
•
count() – Counts array
elements.
•
sort() – Sorts in ascending
order.
•
rsort() – Sorts in
descending order.
•
array_slice() – Extracts a
portion.
These functions simplify array
manipulation, searching, and sorting. They are essential for data handling and
display in dynamic web applications.
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