IS NULL condition in PHP?

IS NULL condition in PHP?

The is_null() function checks whether a variable is NULL or not. This function returns true (1) if the variable is NULL, otherwise it returns false/nothing.

What is null in PHP?

The special null value represents a variable with no value. null is the only possible value of type null. A variable is considered to be null if: it has not been set to any value yet. it has been unset().

Is null or empty PHP?

empty() function in PHP? The isset() function is an inbuilt function in PHP which checks whether a variable is set and is not NULL. This function also checks if a declared variable, array or array key has null value, if it does, isset() returns false, it returns true in all other possible cases.

Is null in PHP MySQL?

MySQL: IS NULL Condition

• Description. The MySQL IS NULL Condition is used to test for a NULL value in a SELECT, INSERT, UPDATE, or DELETE statement.
• Syntax.
• Note.
• Example – With SELECT Statement.
• Example – With INSERT Statement.
• Example – With UPDATE Statement.
• Example – With DELETE Statement.

IS NULL a string in PHP?

When it comes to database columns, PHP’s NULL has no place there. You see, SQL is a string based language. SQL’s NULL must be represented by NULL with no quotes.

How do you set a variable to null in PHP?

In PHP, a variable with no value is said to be of null data type. Such a variable has a value defined as NULL. A variable can be explicitly assigned NULL or its value been set to null by using unset() function.

Which of the following is correct about null in PHP?

All of the above options are correct. Q 22 – Which of the following is correct about NULL? A – NULL is a special type that only has one value: NULL. B – The special constant NULL is capitalized by convention, but actually it is case insensitive.

What means null value?

A null value indicates a lack of a value, which is not the same thing as a value of zero. For example, consider the question “How many books does Adam own?” The answer may be “zero” (we know that he owns none) or “null” (we do not know how many he owns).