Unleash the Power of Each: Embrace the Foreach! You can use the for loop to iterate through an array, but to really shine, you need to use the foreach loop. The foreach loop has the following syntax. foreach ($array as $key => $value) You’ll read the structure like this: For each array as key/value … or For each key/value pair inside of an array. It means that the foreach loop will loop through each array element and you will have access to each key/value pair of each element. This is great if you’re dealing with associative arrays. If the key is a string, you will not be able
Category: PHP
Loop it up: Unleash the power of for loops! I use for loops way more than I use while loops. It seems like most of the time I’m reading items from a database: for loops are perfect for that. I tend to use while loops in Java programs where I need to execute some code until the program terminates; that’s not realistic in PHP. In web-programming, I almost exclusively use for and foreach loops. In most programming languages, the for loop follows the following syntax: for (exp_before; exp_before_loop_body; exp_after) { loop_body } Once PHP encounters the for loop, it looks at the expression exp_before to initialize the necessary variables that are required by the loop. When
What do you do while Doing Do-While Loops? A regular while loop will skip over the loop body if the expression that’s evaluated is never true. But what if we need the contents of the body to be executed at least once? That’s what the do-while loop does for us. <?php $will_execute = false; while ( $will_execute ) { echo “I will execute at least once”; } ?> Looking at the code above, the while loop will never execute since the expression is always false. PHP will just skip over it. In this example, we want the statement to execute at least once. We want PHP to
This Might take a While If you’ve never been introduced to the concept of a loop, think about it this way. Let’s say that you’re looking at an excel sheet. In that excel sheet you have rows that go down the sheet. Each row has some data inside of it. To read the contents of the next row, you move down. You can keep reading the contents of each row up until you reach the last row of that excel sheet. With a loop, you can read the information from a particular row, add 1 to the current row number,
Why Not “Switch” from If/Else? Are you tired of writing if/elseif/elseif/…/else statements? You’re not alone. There is a more elegant way to write such large statements: the PHP switch statement. Let’s take a look at the anatomy of the switch statement. switch ( $arg ) { case “value_1”: expression if matched value_1 break; // terminate case “value_2”: expression if matched value_2 break; // terminate … default: execute if no cases matched } The switch statement accepts an argument. It has a series of “cases” that could potentially match the value of the argument. If it matches, the statements inside of that particular case are executed.
tired of if/else? How about ternary? The PHP Ternary Operator is a way to quickly express if/else statements. The ternary operator follows the following syntax: ( boolean expression ) ? if_true : if_false; If the boolean expression evaluates to true, the “if_true” result is displayed, otherwise the “if_false” result is displayed. Just as a quick recap, the normal if/else syntax looks like the following: <?php $expression = true; if ( $expression ) { // do statement if true } else { // do statement if false } ?> This gets redundant especially when you’re just echoing
Elseif: Between if and Else When you have more than 2 outcomes in your decision making, you’re going to need to use the PHP elseif statement. The elseif keyword goes in between the if and the else keywords. Your primary condition is handled by the if statement. If the condition is met inside of the if statement, there’s no point in testing any other conditions. The code that’s inside of the if statement body is executed and the remainder of the elseif/else statements are skipped. When the condition is not met, PHP will check the elseif statements next. If a condition matches, the code inside of that particular elseif statement body will execute and PHP will skip the remainder
What else is there? The PHP Else statements execute when the if statement’s condition evaluates to false. Remember, the expressions inside of the if statement can only execute when the conditional expression evaluates to true. The else keyword is appended right after the closing curly brace of the if statement. <?php $exercised = false; if ( $exercised ) { echo “You’re being healthy.”; } else { echo “Crickets”; ?> When the programmer chooses to omit the curly braces from the if statement because of a single line expression, the else keyword is appended immediately below the expression that’s
If You Only Knew The PHP if statement is probably the first piece of code that you wrote. “If” statements are conditional statements, meaning that if the expression that they’re evaluating is true, the if statement will allow for the execution of the expressions inside of the if statement body. The anatomy of the if statement looks like this: <?php if ( boolean expression ) { expressions in body } ?> The if statement starts with the word if, followed by an expression enclosed by parentheses. The expression will evaluate to either true or false. If the expression evaluates to true, the expressions inside the
Which Operators Come First? PHP Operator precedence just looks at which operation will be performed first. You’ve seen operator precedence in mathematics. The multiplication and division operators are executed before the addition and subtraction operators. With all of the different operators that we have in PHP, the interpreter needs to know which operation to perform in what order. Let’s look at a basic example in math to get started: 2 + 3 * 5 If you were not aware of operator precedence in mathematics, you may start working from left to right. The answer that you would get would be