[Conclusion] JavaScript Boolean operation value test

Test script

<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();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();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 scripts

Test Results

Boolean (_ boolean_true): True
Boolean (_ boolean_false): false
Boolean (_ undefined): false
Boolean (_ null): false
Boolean (_ INT): True
Boolean (_ int_1): True
Boolean (_ int_0): false
Boolean (_ int _ 0): false
Boolean (_ Nan): false
Boolean (_ string_onestring): True
Boolean (_ string_empty): false
Boolean (_ string_1): True
Boolean (_ string_0): True
Boolean (_ string_true): True
Boolean (_ string_false): True
Boolean (_ string_null): True
Boolean (_ function): True
Boolean (_ array_empty): True
Boolean (_ array_notempty): True
Boolean (_ object_empty): True
Boolean (_ 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: This7Result After a Boolean operation, the result is false. Otherwise, the result is true.