Javascript Boolean operation value test

Test script [javascript] view plaincopy <script type = "text/javascript"> <! -- Var _ boolean_true = true; var _ boolean_false = false; var _ undefined; var _ null = null; var _ int = 10000; var _ int_1 = 1; var _ int_0 = 0; var _ int _ 0 =-0; var _ NaN = NaN; var _ string_onestring = "onestring"; var _ string_empty = ""; var _ string_1 = "1"; var _ string_0 = "0"; var _ string_true = "true"; var _ string_false = "false"; var _ string_null = "null "; var _ string_undefined = "undefined"; var _ Function = function () {}; var _ array_empty = []; var _ array_notempty = [1, 2]; var _ object_empty ={}; var _ object_notempty = {name: 'yourname'}; println ("Boolean (_ boolean_true):" + Boolean (_ boolean_true); println ("Boolean (_ boolean_false ): "+ Boolean (_ boolean_false); println (" Boolean (_ undefined): "+ Boolean (_ undefined); println (" Boolean (_ null ): "+ Boolean (_ null); println (" Boolean (_ int): "+ Boolean (_ int); println (" Boolean (_ int_1): "+ Boolean (_ int_1); println (" Boolean (_ int_0 ): "+ Boolean (_ int_0); println (" Boolean (_ int _ 0): "+ Boolean (_ int _ 0 )); println ("Boolean (_ NaN):" + Boolean (_ NaN); println ("Boolean (_ string_onestring):" + Boolean (_ string_onestring )); println ("Boolean (_ string_empty):" + Boolean (_ string_empty); println ("Boolean (_ string_1):" + Boolean (_ string _ 1); println ("Boolean (_ string_0):" + Boolean (_ string_0); println ("Boolean (_ string_true ): "+ Boolean (_ string_true); println (" Boolean (_ string_false): "+ Boolean (_ string_false); println (" Boolean (_ string_null ): "+ Boolean (_ string_null); println (" Boolean (_ function): "+ Boolean (_ function); println (" Boolean (_ array_empty ): "+ Boolean (_ array_empty); println (" Boolean (_ array_notempty ):" + Boolean (_ array_notempty); println ("Boolean (_ object_empty):" + Boolean (_ object_empty); println ("Boolean (_ object_notempty ): "+ Boolean (_ object_notempty); println ("! _ Boolean_true: "+! _ Boolean_true); println ("! _ Boolean_false: "+! _ Boolean_false); println ("! _ Undefined: "+! _ Undefined); println ("! _ Null: "+! _ Null); println ("! _ Int: "+! _ Int); println ("! _ Int_1: "+! _ Int_1); println ("! _ Int_0: "+! _ Int_0); println ("! _ Int _ 0: "+! _ Int _ 0); println ("! _ NaN: "+! _ NaN); println ("! _ String_onestring: "+! _ String_onestring); println ("! _ String_empty: "+! _ String_empty); println ("! _ String_1: "+! _ String_1); println ("! _ String_0: "+! _ String_0); println ("! _ String_true: "+! _ String_true); println ("! _ String_false: "+! _ String_false); println ("! _ String_null: "+! _ String_null); println ("! _ Function: "+! _ Function); println ("! _ Array_empty: "+! _ Array_empty); println ("! _ Array_notempty: "+! _ Array_notempty); println ("! _ Object_empty: "+! _ Object_empty); println ("! _ Object_notempty: "+! _ Object_notempty); println ("!! _ Boolean_true: "+ !! _ Boolean_true); println ("!! _ Boolean_false: "+ !! _ Boolean_false); println ("!! _ Undefined: "+ !! _ Undefined); println ("!! _ Null: "+ !! _ Null); println ("!! _ Int: "+ !! _ Int); println ("!! _ Int_1: "+ !! _ Int_1); println ("!! _ Int_0: "+ !! _ Int_0); println ("!! _ Int _ 0: "+ !! _ Int _ 0); println ("!! _ NaN: "+ !! _ NaN); println ("!! _ String_onestring: "+ !! _ String_onestring); println ("!! _ String_empty: "+ !! _ String_empty); println ("!! _ String_1: "+ !! _ String_1); println ("!! _ String_0: "+ !! _ String_0); println ("!! _ String_true: "+ !! _ String_true); println ("!! _ String_false: "+ !! _ String_false); println ("!! _ String_null: "+ !! _ String_null); println ("!! _ Function: "+ !! _ Function); println ("!! _ Array_empty: "+ !! _ Array_empty); println ("!! _ Array_notempty: "+ !! _ Array_notempty); println ("!! _ Object_empty: "+ !! _ Object_empty); println ("!! _ Object_notempty: "+ !! _ Object_notempty); function println (s) {s = s | ""; document. writeln (s + "<br/>") ;}// --> </script> run the script test result Boolean (_ boolean_true): trueBoolean (_ boolean_false ): falseBoolean (_ undefined): falseBoolean (_ null): falseBoolean (_ int): trueBoolean (_ int_1): trueBoolean (_ int_0): falseBoolean (_ int _ 0 ): falseBoolean (_ NaN): falseBoolean (_ string_onestring): trueBoolean (_ string_empty): falseBoolean (_ String_1): trueBoolean (_ string_0): trueBoolean (_ string_true): trueBoolean (_ string_false): trueBoolean (_ string_null): trueBoolean (_ function): trueBoolean (_ argument): trueBoolean (_ array_notempty): trueBoolean (_ object_empty): trueBoolean (_ object_notempty): true! _ Boolean_true: false! _ Boolean_false: true! _ Undefined: true! _ Null: true! _ Int: false! _ Int_1: false! _ Int_0: true! _ Int _ 0: true! _ NaN: true! _ String_onestring: false! _ String_empty: true! _ String_1: false! _ String_0: false! _ String_true: false! _ String_false: false! _ String_null: false! _ Function: false! _ Array_empty: false! _ Array_notempty: false! _ Object_empty: false! _ Object_notempty: false !! _ Boolean_true: true !! _ Boolean_false: false !! _ Undefined: false !! _ Null: false !! _ Int: true !! _ Int_1: true !! _ Int_0: false !! _ Int _ 0: false !! _ NaN: false !! _ String_onestring: true !! _ String_empty: false !! _ String_1: true !! _ String_0: true !! _ String_true: true !! _ String_false: true !! _ String_null: true !! _ Function: true !! _ Array_empty: true !! _ Array_notempty: true !! _ Object_empty: true !! _ Object_notempty: true conclusion 0,-0, null, "", false, undefined, Or NaN: the results of these 7 types of results are Boolean and false, otherwise true.