PHP7 scalar Type Declare usage example analysis _php skill

The examples in this article describe the PHP7 scalar type declare usage. Share to everyone for your reference, specific as follows:

In order to improve the execution efficiency, the PHP7 of scalar type (Boolean, floating-point, Integer, character) is added to the function method, which saves the detection of data type.

PHP7 still supports weak type detection, which means that formal parameters can still be declared in the original way.

Scalar declarations have two characteristics:

Force mode (default): reflected on type conversions

Strict mode

Mode declaration: Declare (Strict_types=1);

The default is 0, and the value 1 represents the Strictly validated mode

Type parameters that can be used:

Int-float-bool-string-interfaces-array-callable

Action on the form participation return value type description, optional

Formal parameters

Forced mode
<?php
/**
 * Created by Phpstorm.
 * User:bee
 * DATE:2016/4/22 * time:10:17//
 PHP7 prior to the
Declaration mode
Function Type_weak (... $int) {
  Return Array_sum ($int);
Forced mode PHP7 Declaration mode
//force mode converts all arguments to integer
function sum (int ... $ints)
{
  //array_sum () Returns the value of all the values in an array, with the result of an integer or floating-point number.
  Print_r ($ints);
  echo "<br>";
  Return Array_sum ($ints);
Echo type_weak (2, ' 3 ', 0.11);
echo " 
 

The Operation effect chart is as follows:

Declare the mode as strict mode
<?php
/**
 * Created by Phpstorm.
 * User:bee
 * DATE:2016/4/22 * time:10:17 * *
 //declare must be in the first document
declare (Strict_types=1);
Force mode (default)
function Type_weak (... $int) {return
  array_sum ($int);
}
The force mode
function sum (int ... $ints)
{//array_sum () returns the sum of all the values in the array, with the result of an
  integer or floating-point number.
  Print_r ($ints);
  echo "<br>";
  Return Array_sum ($ints);
Echo type_weak (2, ' 3 ', 0.11);
echo " 
 

The Operation effect chart is as follows:

return value

<?php
/**
 * Created by Phpstorm.
 * User:bee *
 DATE:2016/4/22
 * time:10:17 * *
declare (strict_types=0);
Force mode (default)
function Type_weak (... $int): int{return
  array_sum ($int);
}
Force mode
function sum (int ... $ints): int
{
  //array_sum () returns the sum of all the values in the array with the result of an integer or floating-point number.
  Print_r ($ints);
  echo "<br>";
  Error in strict mode return
  array_sum ($ints) +0.6;
}
Echo type_weak (2, ' 3 ', 0.11);
echo " 
 

The Operation effect chart is as follows:

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