1--TEST-- 2Test mb_substr() function : error conditions - Pass an unknown encoding 3--EXTENSIONS-- 4mbstring 5--FILE-- 6<?php 7/* 8 * Pass an unknown encoding to mb_substr() to test behaviour 9 */ 10 11echo "*** Testing mb_substr() : error conditions ***\n"; 12 13$str = 'Hello, world'; 14$start = 1; 15$length = 5; 16$encoding = 'unknown-encoding'; 17 18try { 19 var_dump( mb_substr($str, $start, $length, $encoding)); 20} catch (\ValueError $e) { 21 echo $e->getMessage() . \PHP_EOL; 22} 23 24?> 25--EXPECT-- 26*** Testing mb_substr() : error conditions *** 27mb_substr(): Argument #4 ($encoding) must be a valid encoding, "unknown-encoding" given 28