| 2. 9. 4. != (Not Equal) |
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JavaScript and Microsoft JScript attempt to convert the expressions to the same data type before evaluating the not equal operation using the following rules: |
True is converted to the number 1, and false is converted to zero before being compared. |
If either of the operands is NaN, the equality operator returns false. |
Null and undefined are equal. |
Null and undefined are not equal to 0 (zero), "" , or false. |
If a string and a number are compared, attempt to convert the string to a number and then check for equality. |
If an object and a string are compared, attempt to convert the object to a string and then check for equality. |
If an object and a number are compared, attempt to convert the object to a number and then check for equality. |
If both operands of an equality operation are objects, the address of the two objects are checked for equality. |
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<html>
<script language="JavaScript">
<!--
if("523" != 523) {
document.write("The string 523 is NOT equal to the number 523");
} else {
document.write("The string 523 is EQUAL to the number 523");
}
-->
</script>
</html>
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Quote from: |
Pure JavaScript (Paperback) |
by R. Allen Wyke (Author), Jason Gilliam (Author), Charlton Ting (Author) |
# Paperback: 1448 pages |
# Publisher: Sams; 1st edition (August 1999) |
# Language: English |
# ISBN-10: 0672315475 |
# ISBN-13: 978-0672315473 |