使用PHP缩短if else语句

Question

i have a question about shorten if else statement. I am trying to make a weather application using OpenWeatherMap api. But i don't like those icons. I want to change the icons like this:

if($desc == 'clear sky'){
  $weather_icon = 'clear_sky.png';
}else
if($desc == 'few clouds'){
  $weather_icon = 'few_clouds.png';
}else
if($desc == 'scattered clouds'){
  $weather_icon = 'scattered_clouds.png';
}else
if($desc == 'broken clouds'){
  $weather_icon = 'broken_clouds.png';
}else
if($desc == ''){
  .....
}
......

So my question is how can i do this with shorten if else or do you have any idea to use different thinks?

Answer 1

Since your description matches what you're looking for you could do this.

if (
    in_array(
        $desc,
        array(
            'clear sky',
            'few clouds',
            'scattered clouds',
            'broken clouds'
        )
    )
) {
    $weather_icon = str_replace(' ', '_', $desc) . '.png';
}

Another option would be to use a map, they they don't always match.

$map = [
    'clear sky' => 'clear_sky.png',
    'few clouds' => 'few_clouds.png',
    'scattered clouds' => 'scattered_clouds.png',
    'broken clouds' => 'broken_clouds.png',
    'thunderstorm with light rain' => 'few_clouds.png',
];

// $api['icon'] references the original icon from the api
$weather_icon = array_key_exists($desc, $map) ? $map[$desc] : $api['icon'];

Answer 2

Arrays are the glue that holds the universe together (if the universe is written in PHP).

$map = [
   'clear sky' => "clear_sky.png",
   'few clouds' =>"few_clouds.png", 
   'scattered clouds' => 'scattered_clouds.png'
   'broken clouds' => 'broken_clouds.png'
];

if (isset($map[$desc])) {
   $weather_icon = $map[$desc];
} 

This allows you to also map unrelated words with image names as well as multiple words to the same image.

Answer 3

If your weather patterns are predictable, you can just use a one liner:

$img = str_replace ( ' ' , '_', $desc ) . '.png';

However if you have a list that you cannot just alter dynaically you can use this:

$descriptions = [
     'clear sky'=>'clear_sky',
     'few clouds'=>'few_clouds',
     'scattered clouds'=>'scattered_clouds',    
     'broken clouds'=>'broken_clouds',    
];

$defaultImg = 'some_empty';

$img = !empty($desc) ? $descriptions[$desc] : $defaultImg;
$img = $img . 'png';

Answer 4

<?php
$desc = "clear sky";
$weather_icon = str_replace(" ","_",$desc).".png";
echo $weather_icon;
?>

Answer 5

It looks like you have a some fixed notation. You could use this:

<?php
$desc = 'clear sky';
convertDescriptionToImage( $desc );

function convertDescriptionToImage( $description )
{
    $arrayCodes = ["clear sky", "few clouds"];
    if ( TRUE == in_array( $description, $arrayCodes ) )
    {
        return str_replace( " ", "_", "$description.png" );
    }

    die( "$description not found" );
}