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Curing the
Common Loop
@adamwathan
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$totalRevenue = 0;
$minSales = 75000;
foreach ($employees as $employee) {
$employeeType = $employee->getType();
if ($employeeType == 'Sales') {
$customers = $employee->getCustomers();
foreach ($customers as $customer) {
$customerTotalSales = 0;
foreach ($customer->getOrders() as $order) {
$customerTotalSales += $order->total;
}
if ($customerTotalSales >= $minSales) {
$totalRevenue += $customerTotalSales;
}
}
}
}
return $totalRevenue;
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Higher Order
FUNCTIONS
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Route::get('/', function () {
return view('welcome');
});
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Mail::send('order-shipped', $data, function ($m) {
$m->to($this->customer->email);
$m->subject("Your order has shipped!");
});
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DB::transaction(function () use ($user) {
$user->subscription()->delete();
$user->update([
'cancelled_at' => Carbon::now()
]);
});
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Afford more powerful
ABSTRACTIONS
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For example…
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$customerEmails = [];
foreach ($customers as $customer) {
$customerEmails[] = $customer->email;
}
return $customerEmails;
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$stockTotals = [];
foreach ($inventoryItems as $item) {
$stockTotals[] = [
'product' => $item->productName,
'total_value' => $item->quantity * $item->price,
];
}
return $stockTotals;
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$customerEmails = [];
foreach ($customers as $customer) {
$customerEmails[] = $customer->email;
}
return $customerEmails;
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$customerEmails = [];
foreach ($customers as $customer) {
$email = $customer->email;
$customerEmails[] = $email;
}
return $customerEmails;
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$stockTotals = [];
foreach ($inventoryItems as $item) {
$stockTotals[] = [
'product' => $item->productName,
'total_value' => $item->quantity * $item->price,
];
}
return $stockTotals;
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$stockTotals = [];
foreach ($inventoryItems as $item) {
$stockTotal = [
'product' => $item->productName,
'total_value' => $item->quantity * $item->price,
];
$stockTotals[] = $stockTotal;
}
return $stockTotals;
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$stockTotals = [];
foreach ($inventoryItems as $item) {
$stockTotal = [
'product' => $item->productName,
'total_value' => $item->quantity * $item->price,
];
$stockTotals[] = $stockTotal;
}
return $stockTotals;
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$results = [];
foreach ($items as $item) {
$result = [
'product' => $item->productName,
'total_value' => $item->quantity * $item->price,
];
$results[] = $result;
}
return $results;
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$results = [];
foreach ($items as $item) {
$result = $item->email;
$results[] = $result;
}
return $results;
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$results = [];
foreach ($items as $item) {
$result = $item->email;
$results[] = $result;
}
return $results;
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$callback = function ($item) {
return $item->email;
};
$results = [];
foreach ($items as $item) {
$result = $callback($item);
$results[] = $result;
}
return $results;
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$results = [];
foreach ($items as $item) {
$result = [
'product' => $item->productName,
'total_value' => $item->quantity * $item->price,
];
$results[] = $result;
}
return $results;
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$callback = function ($item) {
return [
'product' => $item->productName,
'total_value' => $item->quantity * $item->price,
];
};
$results = [];
foreach ($items as $item) {
$result = $callback($item);
$results[] = $result;
}
return $results;
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$callback = function ($item) {
return [
'product' => $item->productName,
'total_value' => $item->quantity * $item->price,
];
};
$results = [];
foreach ($items as $item) {
$result = $callback($item);
$results[] = $result;
}
return $results;
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$callback = function ($item) {
return $item->email;
};
$results = [];
foreach ($items as $item) {
$result = $callback($item);
$results[] = $result;
}
return $results;
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function array_map($callback, $items) {
}
$results = [];
foreach ($items as $item) {
$result = $callback($item);
$results[] = $result;
}
return $results;
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$customerEmails = [];
foreach ($customers as $customer) {
$customerEmails[] = $customer->email;
}
return $customerEmails;
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$customerEmails = array_map(function ($customer) {
return $customer->email;
}, $customers);
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$stockTotals = [];
foreach ($inventoryItems as $item) {
$stockTotals[] = [
'product' => $item->productName,
'total_value' => $item->quantity * $item->price,
];
}
return $stockTotals;
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$stockTotals = [];
foreach ($inventoryItems as $item) {
$stockTotals[] = [
'product' => $item->productName,
'total_value' => $item->quantity * $item->price,
];
}
return $stockTotals;
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$stockTotals = array_map(function ($inventoryItem) {
return [
'product' => $item->productName,
'total_value' => $item->quantity * $item->price,
];
}, $inventoryItems);
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Another…
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$outOfStockProducts = [];
foreach ($products as $product) {
if ($product->isOutOfStock()) {
$outOfStockProducts[] = $product;
}
}
return $outOfStockProducts;
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$expensiveProducts = [];
foreach ($products as $product) {
if ($product->price > 100) {
$expensiveProducts[] = $product;
}
}
return $expensiveProducts;
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$results = [];
foreach ($items as $item) {
if ($item->price > 100) {
$results[] = $item;
}
}
return $results;
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$outOfStockProducts = [];
foreach ($products as $product) {
if ($product->isOutOfStock()) {
$outOfStockProducts[] = $product;
}
}
return $outOfStockProducts;
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$results = [];
foreach ($items as $item) {
if ($item->isOutOfStock()) {
$results[] = $item;
}
}
return $results;
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$results = [];
foreach ($items as $item) {
if ($item->isOutOfStock()) {
$results[] = $item;
}
}
return $results;
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$results = [];
foreach ($items as $item) {
if ($item->price > 100) {
$results[] = $item;
}
}
return $results;
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$callback = function ($item) {
return $item->price > 100;
};
$results = [];
foreach ($items as $item) {
if ($callback($item)) {
$results[] = $item;
}
}
return $results;
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$results = [];
foreach ($items as $item) {
if ($item->isOutOfStock()) {
$results[] = $item;
}
}
return $results;
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$callback = function ($item) {
return $item->isOutOfStock();
};
$results = [];
foreach ($items as $item) {
if ($callback($item)) {
$results[] = $item;
}
}
return $results;
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$callback = function ($item) {
return $item->isOutOfStock();
};
$results = [];
foreach ($items as $item) {
if ($callback($item)) {
$results[] = $item;
}
}
return $results;
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$callback = function ($item) {
return $item->price > 100;
};
$results = [];
foreach ($items as $item) {
if ($callback($item)) {
$results[] = $item;
}
}
return $results;
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function array_filter($items, $callback) {
$results = [];
foreach ($items as $item) {
if ($callback($item)) {
$results[] = $item;
}
}
return $results;
}
$results = [];
foreach ($items as $item) {
if ($callback($item)) {
$results[] = $item;
}
}
return $results;
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$outOfStockProducts = [];
foreach ($products as $product) {
if ($product->isOutOfStock()) {
$outOfStockProducts[] = $product;
}
}
return $outOfStockProducts;
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$outOfStockProducts = array_filter($products, function ($product) {
return $product->isOutOfStock();
});
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$expensiveProducts = [];
foreach ($products as $product) {
if ($product->price > 100) {
$expensiveProducts[] = $product;
}
}
return $expensiveProducts;
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$expensiveProducts = array_filter($products, function ($product) {
return $product->price > 100;
});
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function getSalesEmails($employees) {
$emails = [];
foreach ($employees as $employee) {
if ($employee->department === 'Sales') {
$emails[] = $employee->email;
}
}
return $emails;
}
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function getSalesEmails($employees) {
$emails = [];
foreach ($employees as $employee) {
if ($employee->department === 'Sales') {
$emails[] = $employee->email;
}
}
return $emails;
}
…map?
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function getSalesEmails($employees) {
$emails = [];
foreach ($employees as $employee) {
if ($employee->department === 'Sales') {
$emails[] = $employee->email;
}
}
return $emails;
}
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Thinking in
STEPS
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function getSalesEmails($employees) {
$emails = [];
foreach ($employees as $employee) {
if ($employee->department === 'Sales') {
$emails[] = $employee->email;
}
}
return $emails;
}
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function getSalesEmails($employees) {
$salesEmployees = array_filter($employees, function ($employee) {
return $employee->department == 'Sales';
});
$emails = [];
foreach ($employees as $employee) {
if ($employee->department === 'Sales') {
$emails[] = $employee->email;
}
}
return $emails;
}
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function getSalesEmails($employees) {
$salesEmployees = array_filter($employees, function ($employee) {
return $employee->department == 'Sales';
});
$emails = [];
foreach ($employees as $employee) {
if ($employee->department === 'Sales') {
$emails[] = $employee->email;
}
}
return $emails;
}
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function getSalesEmails($employees) {
$salesEmployees = array_filter($employees, function ($employee) {
return $employee->department == 'Sales';
});
$emails = [];
foreach ($employees as $employee) {
if ($employee->department === 'Sales') {
$emails[] = $employee->email;
}
}
return $emails;
}
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function getSalesEmails($employees) {
$salesEmployees = array_filter($employees, function ($employee) {
return $employee->department == 'Sales';
});
$emails = [];
foreach ($salesEmployees as $employee) {
if ($employee->department === 'Sales') {
$emails[] = $employee->email;
}
}
return $emails;
}
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function getSalesEmails($employees) {
$salesEmployees = array_filter($employees, function ($employee) {
return $employee->department == 'Sales';
});
$emails = [];
foreach ($salesEmployees as $employee) {
if ($employee->department === 'Sales') {
$emails[] = $employee->email;
}
}
return $emails;
}
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function getSalesEmails($employees) {
$salesEmployees = array_filter($employees, function ($employee) {
return $employee->department == 'Sales';
});
$emails = [];
foreach ($salesEmployees as $employee) {
$emails[] = $employee->email;
}
return $emails;
}
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function getSalesEmails($employees) {
$salesEmployees = array_filter($employees, function ($employee) {
return $employee->department == 'Sales';
});
$emails = [];
foreach ($salesEmployees as $employee) {
$emails[] = $employee->email;
}
return $emails;
}
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function getSalesEmails($employees) {
$salesEmployees = array_filter($employees, function ($employee) {
return $employee->department == 'Sales';
});
$emails = [];
foreach ($salesEmployees as $employee) {
$emails[] = $employee->email;
}
return $emails;
}
Map!
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function getSalesEmails($employees) {
$salesEmployees = array_filter($employees, function ($employee) {
return $employee->department == 'Sales';
});
$emails = [];
foreach ($salesEmployees as $employee) {
$emails[] = $employee->email;
}
return $emails;
}
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function getSalesEmails($employees) {
$salesEmployees = array_filter($employees, function ($employee) {
return $employee->department == 'Sales';
});
$emails = array_map(function ($employee) {
return $employee->email;
}, $salesEmployees);
return $emails;
}
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function getSalesEmails($employees) {
$salesEmployees = array_filter($employees, function ($employee) {
return $employee->department == 'Sales';
});
$emails = array_map(function ($employee) {
return $employee->email;
}, $salesEmployees);
return $emails;
}
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Things I
HATE
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#1. FOR LOOPS
#2. CONDITIONALS
#3. TEMP VARIABLES
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function getSalesEmails($employees) {
$salesEmployees = array_filter($employees, function ($employee) {
return $employee->department == 'Sales';
});
$emails = array_map(function ($employee) {
return $employee->email;
}, $salesEmployees);
return $emails;
}
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function getSalesEmails($employees) {
$salesEmployees = array_filter($employees, function ($employee) {
return $employee->department == 'Sales';
});
$emails = array_map(function ($employee) {
return $employee->email;
}, $salesEmployees);
return $emails;
}
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function getSalesEmails($employees) {
$salesEmployees = array_filter($employees, function ($employee) {
return $employee->department == 'Sales';
});
$emails = array_map(function ($employee) {
return $employee->email;
}, $salesEmployees);
return $emails;
}
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Inline
TEMP
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function getSalesEmails($employees) {
$salesEmployees = array_filter($employees, function ($employee) {
return $employee->department == 'Sales';
});
$emails = array_map(function ($employee) {
return $employee->email;
}, $salesEmployees);
return $emails;
}
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function getSalesEmails($employees) {
$salesEmployees = array_filter($employees, function ($employee) {
return $employee->department == 'Sales';
});
return array_map(function ($employee) {
return $employee->email;
}, $salesEmployees);
}
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function getSalesEmails($employees) {
$salesEmployees = array_filter($employees, function ($employee) {
return $employee->department == 'Sales';
});
return array_map(function ($employee) {
return $employee->email;
}, $salesEmployees);
}
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function getSalesEmails($employees) {
$salesEmployees = array_filter($employees, function ($employee) {
return $employee->department == 'Sales';
});
return array_map(function ($employee) {
return $employee->email;
}, $salesEmployees);
}
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function getSalesEmails($employees) {
$salesEmployees = array_filter($employees, function ($employee) {
return $employee->department == 'Sales';
});
return array_map(function ($employee) {
return $employee->email;
}, $salesEmployees);
}
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function getSalesEmails($employees) {
$salesEmployees = array_filter($employees, function ($employee) {
return $employee->department == 'Sales';
});
return array_map(function ($employee) {
return $employee->email;
}, array_filter($employees, function ($employee) {
return $employee->department == 'Sales';
}));
}
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function getSalesEmails($employees) {
$salesEmployees = array_filter($employees, function ($employee) {
return $employee->department == 'Sales';
});
return array_map(function ($employee) {
return $employee->email;
}, array_filter($employees, function ($employee) {
return $employee->department == 'Sales';
}));
}
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function getSalesEmails($employees) {
return array_map(function ($employee) {
return $employee->email;
}, array_filter($employees, function ($employee) {
return $employee->department == 'Sales';
}));
}
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The Problem With
PRIMITIVES
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# => hello_there_laracon
function toCamelCase($snakeString) {
return lcfirst(
str_replace(' ', '',
ucwords(str_replace('_', ' ', $snakeString))
)
);
}
# => helloThereLaracon
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# => hello_there_laracon
function toCamelCase($snakeString) {
return $snakeString->replace('_', ' ')
->ucwords()
->replace(' ', '')
->lcfirst();
}
# => helloThereLaracon
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Introducing
COLLECTIONS
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function getSalesEmails($employees) {
$salesEmployees = array_filter($employees, function ($employee) {
return $employee->department == 'Sales';
});
$emails = array_map(function ($employee) {
return $employee->email;
}, $salesEmployees);
return $emails;
}
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function getSalesEmails($employees) {
$salesEmployees = array_filter($employees, function ($employee) {
return $employee->department == 'Sales';
});
$emails = array_map(function ($employee) {
return $employee->email;
}, $salesEmployees);
return $emails;
}
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function getSalesEmails($employees) {
$salesEmployees = $employees->filter(function ($employee) {
return $employee->department == 'Sales';
});
$emails = array_map(function ($employee) {
return $employee->email;
}, $salesEmployees);
return $emails;
}
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function getSalesEmails($employees) {
$salesEmployees = $employees->filter(function ($employee) {
return $employee->department == 'Sales';
});
$emails = array_map(function ($employee) {
return $employee->email;
}, $salesEmployees);
return $emails;
}
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function getSalesEmails($employees) {
$salesEmployees = $employees->filter(function ($employee) {
return $employee->department == 'Sales';
});
$emails = $salesEmployees->map(function ($employee) {
return $employee->email;
});
return $emails;
}
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function getSalesEmails($employees) {
return $employees->filter(function ($employee) {
return $employee->department == 'Sales';
})->map(function ($employee) {
return $employee->email;
});
}
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Let’s write
SOME CODE!
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http://www.fullstackradio.com
FULL
RADIO
STACK
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@adamwathan
adamwathan.me