How do I get a part of a string in php?
If I have a string `"_jpg.jpg"` I want to remove the `"_"` and the last part `".jpg"`. Thus, returning the string `"jpg"`. What php function should I use? 
How do I get a part of a string in php?
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If I have a string `"_jpg.jpg"` I want to remove the `"_"` and the last part `".jpg"`. Thus, returning the string `"jpg"`. What php function should I use? 