# Programming Fundamentals/Arrays/PHP

## arrays.php

```<?php

// This program uses arrays to display temperature conversion tables
// and temperature as an array subscript to find a given conversion.
//
// References:
//     https://www.mathsisfun.com/temperature-conversion.html
//     https://en.wikibooks.org/wiki/PHP_Programming

function build_c(\$size)
{
\$c = array();

for (\$index = 0; \$index <= \$size; \$index++)
{
\$value = \$index * 9 / 5 + 32;
\$c[\$index] = \$value;
}

return \$c;
}

function build_f(\$size)
{
\$f = array();

for (\$index = 0; \$index <= \$size; \$index++)
{
\$value = (\$index - 32) * 5 / 9;
\$f[\$index] = \$value;
}

return \$f;
}

function display_array(\$name, \$array)
{
for (\$index = 0; \$index < count(\$array); \$index++)
{
echo(\$name . "[" . \$index . "] = " . \$array[\$index] ."\n");
}
}

function find_temperature(\$c, \$f)
{
\$size = minimum(count(\$c), count(\$f));
do
{
echo("Enter a temperature between 1 and " . (\$size - 1) . "\n");
} while (\$temp < 1 or \$temp > \$size - 1);
echo(\$temp . "° Celsius is " . \$c[\$temp] . "° Fahrenheit\n");
echo(\$temp . "° Fahrenheit is " . \$f[\$temp] . "° Celsius\n");
}

function minimum(\$value1, \$value2)
{
if(\$value1 < \$value2)
{
\$result = \$value1;
}
else
{
\$result = \$value2;
}

return \$result;
}

function main()
{
\$c = build_c(100);
\$f = build_f(212);
display_array("C", \$c);
display_array("F", \$f);
find_temperature(\$c, \$f);
}

main();

?>
```

## Try It

Copy and paste the code above into one of the following free online development environments or use your own PHP compiler / interpreter / IDE.