3v4l.org

run code in 500+ PHP versions simultaneously
<?php foreach([1,2,3,18,19,308,309] as $n) { echo "1e$n\t"; var_dump((float) "1e$n"); }
Output for 7.4.0 - 7.4.33, 8.0.1 - 8.0.30, 8.1.0 - 8.1.34, 8.2.0 - 8.2.32, 8.3.0 - 8.3.33, 8.4.1 - 8.4.24, 8.5.0 - 8.5.9
1e1 float(10) 1e2 float(100) 1e3 float(1000) 1e18 float(1.0E+18) 1e19 float(1.0E+19) 1e308 float(1.0E+308) 1e309 float(INF)

preferences:
111.86 ms | 1300 KiB | 4 Q