PHP/Data Type/Integer — различия между версиями
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Версия 10:37, 26 мая 2010
Содержание
- 1 Add an Integer value
- 2 Add a PHP block and create a variable that holds an integer
- 3 Addendum: finding the largest integer
- 4 Adding two integers together
- 5 Add the two integer values and print the result.
- 6 ++$answer and $answer++
- 7 Assign an integer value this way
- 8 Calculating a date interval with epoch timestamps
- 9 Calculating Discount
- 10 Divide the two values and print the result
- 11 Integer calculation
- 12 Integers can be specified using any of the following syntaxes
- 13 Integer value compare with equal sign
- 14 Integer values can be signed and unsigned in the range from �2,147,483,648 to 2,147,483,647.
- 15 Int value overflow
- 16 Multiply the two values and print the result
- 17 Storing Integers in PHP
- 18 Subtracted an Integer value
- 19 Subtract the two values and print the result
- 20 To specify a number in hexadecimal, precede it with 0x.
- 21 Using typecasting to convert numbers to strings
Add an Integer value
<?
$origVar = 100;
$origVar += 25;
echo "<P>Added a value, now it"s $origVar</P>";
?>
Add a PHP block and create a variable that holds an integer
<?
# create a variable that holds an integer
$intVar = "9554215464";
echo "<P>integer: $intVar</P>";
?>
Addendum: finding the largest integer
<?
function maxint(){
$to_test = 2;
while(1){
$last = $to_test;
$to_test = 2 * $to_test;
if (($to_test < $last) || (!is_int($to_test))){
return($last + ($last - 1));
}
}
}
$maxint = maxint();
print("Maxint is $maxint<BR>");
?>
Adding two integers together
<?php
$var1 = 5;
$var2 = 2;
$answer = $var1 + $var2;
print "$var1 plus $var2 equals $answer.";
?>
Add the two integer values and print the result.
<?
$a = 85;
$b = 24;
echo "<P>Original value of \$a is $a and \$b is
$b</P>";
$c = $a + $b;
echo "<P>Added \$a and \$b and got $c</P>";
?>
++$answer and $answer++
<?php
$answer = 5;
echo (++$answer)." ";
echo "$answer<BR>";
$answer = 5;
echo ($answer++)." ":
echo $answer;
?>
Assign an integer value this way
<?php
$myint = 10;
echo $myint . "<br />";
echo (int) $myint . "<br />";
$myint = 10 / 3;
echo (int) $myint . "<br />";
?>
Calculating a date interval with epoch timestamps
<?php
$birthday = 163727100;
$gestation = 36 * 7 * 86400; // 36 weeks
$whoopee_made = $birthday - $gestation;
?>
Calculating Discount
<HTML>
<BODY>
<H1><CENTER>Calculating Discount</CENTER></H1>
<?php
$price = 200;
$qty = 10;
echo "<H4>Original price is $price</H4>";
if ($qty =10) {
$discount=10;
}elseif ($qty <=20) {
$discount=15;
}elseif (qty <=30) {
$discount=20;
}elseif($qty <=40){
$discount=25;
}
echo "<H4>Discount is $discount percent</H4>";
echo "<H4>Price after discount is ", (($price * (100 - $discount)/ 100)), "</H4>";
?>
</BODY>
</HTML>
Divide the two values and print the result
<?
$a = 85;
$b = 24;
echo "<P>Original value of \$a is $a and \$b is
$b</P>";
$c = $a / $b;
echo "<P>Divided \$a by \$b and got $c</P>";
?>
Integer calculation
$i = 1; $j = 2;
print "$i $j";
$i++; $j *= 2;
print "$i $j";
$i++; $j *= 2;
print "$i $j";
$i++; $j *= 2;
print "$i $j";
$i++; $j *= 2;
print "$i $j";
Integers can be specified using any of the following syntaxes
<?
$a = 1234; # decimal number
$a = -123; # a negative number
$a = 0123; # octal number (equivalent to 83 decimal)
$a = 0x12; # hexadecimal number (equivalent to 18 decimal)
?>
Integer value compare with equal sign
<?
$a=100;
$b=true;
echo "a = $a<br>";
echo "b = $b<br>";
if($a==$b)
echo "a "is equal to" b!"; ?>
Integer values can be signed and unsigned in the range from �2,147,483,648 to 2,147,483,647.
<?php
$i = 0x7FFFFFFF;
echo "$i is " . (is_int($i) ? "an integer" : "a float") . "\n";
$i++;
echo "$i is " . (is_int($i) ? "an integer" : "a float") . "\n";
?>
Int value overflow
<?
$too_big = 111;
for ($count = 0; $count < 5; $count++) {
$too_big = 1000 * $too_big;
print("Is $too_big still an integer?<BR>");
}
?>
Multiply the two values and print the result
<?
$a = 85;
$b = 24;
echo "<P>Original value of \$a is $a and \$b is
$b</P>";
$c = $a * $b;
echo "<P>Multiplied \$a and \$b and got $c</P>";
?>
Storing Integers in PHP
<?php
$my_int = 50; /* Standard Decimal Notation */
$my_int = O62; /* Same number, Octal Notation (starts with the letter O)*/
$my_int = 0x32; /* Hexadecimal Notation */
?>
Subtracted an Integer value
<?
$origVar = 100;
$origVar -= 12;
echo "<P>Subtracted a value, now it"s $origVar</P>";
?>
Subtract the two values and print the result
<?
$a = 85;
$b = 24;
echo "<P>Original value of \$a is $a and \$b is
$b</P>";
$c = $a - $b;
echo "<P>Subtracted \$b from \$a and got $c</P>";
?>
To specify a number in hexadecimal, precede it with 0x.
//To assign the number 68, you would use this:
$hexnum = 0x44;
print $hexnum;
Using typecasting to convert numbers to strings
<?php
$i = 123456;
$f = 98765.567;
echo "\$i = " . (string)$i . "\n";
echo "\$f = " . (string)$f . "\n";
?>