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10 Cards in this Set
- Front
- Back
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What actual underlying values are represented by TRUE and FALSE?
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In PHP, TRUE represents the value 1 and FALSE represents NULL, which can be thought
of as “nothing” and is output as the empty string. |
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What are the simplest two forms of expressions?
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The simplest forms of expressions are literals (such as numbers and strings) and
variables, which simply evaluate to themselves. |
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What is the difference between unary, binary, and ternary operators?
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The difference between unary, binary, and ternary operators is the number of
operands each requires (one, two, and three, respectively). |
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What is the best way to force your own operator precedence?
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The best way to force your own operator precedence is to place parentheses around
subexpressions to which you wish to give high precedence. |
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What is meant by operator associativity?
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Operator associativity refers to the direction of processing (left to right or right to
left). |
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When would you use the === (identity) operator?
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You use the identity operator when you wish to bypass PHP’s automatic operand
type changing (also called type casting). |
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Name the three conditional statement types.
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The three conditional statement types are if, switch, and the ? operator.
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What command can you use to skip the current iteration of a loop and move on
to the next one? |
To skip the current iteration of a loop and move on to the next one, use a con
tinue statement. |
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Why is a for loop more powerful than a while loop?
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Loops using for statements are more powerful than while loops because they support
two additional parameters to control the loop handling. |
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How do if and while statements interpret conditional expressions of different data
types? |
Most conditional expressions in if and while statements are literal (or Boolean)
and therefore trigger execution when they evaluate to TRUE. Numeric expressions trigger execution when they evaluate to a nonzero value. String expressions trigger execution when they evaluate to a nonempty string. A NULL value is evaluated as false and therefore does not trigger execution. |
