JavaScript Type Conversion

JavaScript Type Conversion Table

The table below shows the result of converting different JavaScript values to Number, String, and Boolean:

Original Value	Converted to Number	Converted to String	Converted to Boolean	Try it
false	0	"false"	false	Try it »
true	1	"true"	true	Try it »
0	0	"0"	false	Try it »
1	1	"1"	true	Try it »
"0"	0	"0"	true	Try it »
"1"	1	"1"	true	Try it »
NaN	NaN	"NaN"	false	Try it »
Infinity	Infinity	"Infinity"	true	Try it »
-Infinity	-Infinity	"-Infinity"	true	Try it »
""	0	""	false	Try it »
"20"	20	"20"	true	Try it »
"twenty"	NaN	"twenty"	true	Try it »
[ ]	0	""	true	Try it »
[20]	20	"20"	true	Try it »
[10,20]	NaN	"10,20"	true	Try it »
["twenty"]	NaN	"twenty"	true	Try it »
["ten","twenty"]	NaN	"ten,twenty"	true	Try it »
function(){}	NaN	"function(){}"	true	Try it »
{ }	NaN	"[object Object]"	true	Try it »
null	0	"null"	false	Try it »
undefined	NaN	"undefined"	false	Try it »

Note: Values in quotes ("") indicate string values. Values in red indicate values (some) programmers might not expect.

For a tutorial about JavaScript Type Conversion, read our JavaScript Type Conversion Tutorial.