Operators And Expressions In Php — Part 1 MCQs with Explanations

If you need to output something onto the screen you’ll need to use echo or print_r.

The statement should be print_r(‘Hello World’) to print Hello world. Also if there is only one line then there is no requirement of a semicolon, but it is better to use it.

In PHP, all variables are case-sensitive.

# is a single line comment.

You can use tags like italics, bold etc. inside php script.

It would have printed echo “Hello world” if the statement was echo “echo ”Hello World””;.

You can not have php tags inside a php tag.

To print red remove the .

Use of undefined constant red.

It has to be $color1 = “red”; and $color2 = “green”; therefore the error.

The variable contains the last value which has been assigned.

+ does not return 1 if the variables are equal.

+ just returns the numeric value even though it is inside double quotes.

+ can be used to add to integer values which are enclosed by double-quotes.

+ gives the value 1 and . is used to give join 1 and grey.

In an echo statement the comma operator is used to join strings.

Echo can print two variables which are seperated by a comma.

In the echo statement the {$cars[0]} is replaced by the 1st element in cars that is Volvo.

The print statement will print what ever is present inside the double-quotes.

Print can be used with or without parantheses.

Print statement can be used to output a specific array member.

The above syntax will produce an error, unlike the echo statement.

Since both the strings are equal the result 1 is printed on the screen.

You can use the dot operator like in echo but you can not use the comma operator to do the same.

Constants do not need a $ before them, they are referenced by their variable names itself.

In a class constants should be defined const MIN_VALUE = 0.0;const MAX_VALUE = 1.0; instead.

__LINE__ is a magical constant that gives the current line number and cannot be used a variable/constant name.

Keyword like IF cannot be used as constant names.

Constants can be set as values for other constants.

${VAR_NAME} creates a new variable which is not same as VAR_NAME.

Class constants cannot be defined outside class.

Variable z will store 10 + 5 because 10 + 5 is given in double-quotes.

Again since the variables are inside double quotes we get this result.

Normal addition of variables x, y and z occurs and result of 8 will be displayed.

% is the modulo operator. Unlike in C we can use it get reminder or floating point numbers in PHP.

The expression is considered as ($x%$y)%z in this case (10%4)%3 which is 2.

First ($z – $y) is evalulated then -$z/($z – $y) is evaluated this results in 1 which is added to $x + $y therefore we get 51.

First the * is evaluated then / followed by + therefore we can rewrite this expression as 4 +((- 3 * 11) / 4) which results in -4.25.

First $x / $y is evaluated then this is divided by $z therefore we get 0.875.

Variables should start with a $ symbol, since one, two, three, four don’t begin with $ symbol we’ll get an error.