The IF statements work like this:
If nesting (multiple IF statements) is necessary, replace 'Returned result if false' with another complete IF statement like this (line-breaks inserted for clarity):
So, in your example, it would be like this (line-breaks inserted for clarity):
{if(condition, 'Returned result if true', 'Returned result if false')}
If nesting (multiple IF statements) is necessary, replace 'Returned result if false' with another complete IF statement like this (line-breaks inserted for clarity):
{if(condition1, 'Returned if true',
if(condition2, 'Returned if true',
if(condition3, 'Returned if true',
if(condition4, 'Returned if true',
if(condition5, 'Returned if true', 'Returned if all conditions false'
))))}
So, in your example, it would be like this (line-breaks inserted for clarity):
{if(random == 1, 'Text string 1.',
if(random == 2, 'Text string 2.',
if(random == 3, 'Text string 3.',
if(random == 4, 'Text string 4.',
'Text string 5.'
))))}