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Boolean（布爾）對象用於將非布爾值轉換為布爾值（true 或者 false）。
檢查布爾值
檢查布爾對象是 true 還是 false。
原始碼樣本:
<!DOCTYPE html><html><body><script>var b1=new Boolean(0);var b2=new Boolean(1);var b3=new Boolean("");var b4=new Boolean(null);var b5=new Boolean(NaN);var b6=new Boolean("false");document.write("0 is boolean "+ b1 +"<br>");document.write("1 is boolean "+ b2 +"<br>");document.write("An empty string is boolean "+ b3 + "<br>");document.write("null is boolean "+ b4+ "<br>");document.write("NaN is boolean "+ b5 +"<br>");document.write("The string 'false' is boolean "+ b6 +"<br>");</script></body></html>
測試結果:
0 is boolean false1 is boolean trueAn empty string is boolean falsenull is boolean falseNaN is boolean falseThe string 'false' is boolean true
建立 Boolean 對象
Boolean 對象代表兩個值:"true" 或者 "false"
下面的代碼定義了一個名為 myBoolean 的布爾對象：
var myBoolean=new Boolean();
如果布爾對象無初始值或者其值為:
0-0null""falseundefinedNaN
那麼對象的值為 false。否則，其值為 true（即使當自變數為字串 "false" 時）！
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