Comparing between variables having a string is failed.

[Kray-G]

Here is an example to be failed.

function gt(a, b)  { return a > b; }
function lt(a, b)  { return a < b; }
function ge(a, b)  { return a >= b; }
function le(a, b)  { return a <= b; }
function lge(a, b) { return a <=> b; } // will be successful.
try { gt("a", "b");  } catch (e) { System.println(e.what()); }
try { lt("a", "b");  } catch (e) { System.println(e.what()); }
try { ge("a", "b");  } catch (e) { System.println(e.what()); }
try { le("a", "b");  } catch (e) { System.println(e.what()); }
try { lge("a", "b"); } catch (e) { System.println(e.what()); } // nothing's displayed.

It is okay when comparing two strings directly.

System.println("a" > "b");