var breakpoints = [ 25000 , 50000 , 150000 ]; 
my @breakpoints = ( 25000 , 50000 , 150000 );

##</code><code>##

 
breakpoints.push(50123);
push(@breakpoints, 50123);

##</code><code>##

breakpoints.sort();
var return_value = breakpoints[breakpoints.indexOf(50123) - 1];

@breakpoints = sort @breakpoints;
# Use your favourite perl method for indexOf like above