1:parseint (String): The function is parsed from the beginning of the string, returning an integer
parseint ("123hua"); // output 123parseint ("123"); // output 123parseint ("12.3"); // output of parseint ("Hua"); // Output Nan
2: In addition the parseint () method has other modes, that is, binary, octal, hexadecimal, or any other binary string can be converted to an integer
parseint ("ten", +); // output of parseint ("Ten", 2); // Output 2parseint ("10s", 2); // Output 2parseint ("Ten", 8); // output 8parseint ("ten"); // output of parseint ("0x10"); // output 0x 16 representation of the binary
3.parseFloat (): This function is similar to the parseint () method.
Parsefloat ("123hua"); // output 123parsefloat ("123"); // output 123parsefloat ("12.3"); // output 12.3parsefloat ("Hua"); // Output Nan
4.Number (): Coercion of type conversions, similar to the parseint () and parsefloat () methods, except that it transforms the entire value, not the partial value.
Number (false ) // output 0 number (true ) // Output 1 number (undefined) // output NaN Number (null ) output 0 number ("1.2") // output 1.2 Number ("n") // output number ("1.2.3") Span style= "color: #008000;" >// output NaN number (new Object ()) Span style= "color: #008000;" >// output NaN
The ToString () method of the 5:number type is special, and it has two modes, the default mode and the base mode.
With the default mode, the ToString () method simply outputs a numeric value (whether integer, floating point, or scientific notation) with the corresponding string.
var iNum = ten; alert (inum.tostring (2)); // output "1010"Alert (inum.tostring (8)); // output "a" alert (inum.tostring ()); // output "A" (). toString (); // Output "" (a). ToString (2); // output "1100" "N". toString (2); // Output ""
The ToString () method of the 6:boolean type simply outputs "true" or "false"
var false ; alert (bfound.tostring ()); // output "false"
7: Bitwise operators operate on the bottom of the number (that is, the 32 digits of the number).
Bitwise arithmetic not is represented by a negative number (~)
// var iNum1 = 25; // 25 equals 00000000000000000000000000011001 var iNum2 = ~inum1; // convert to 11111111111111111111111111100110 alert (iNum2); // output " -26" // var iNum1 = 25; var iNum2 =-inum1-1;alert (INUM2); // output -26
Bitwise operation and by the ampersand (&), directly to the binary form of the number of operations, are 1 1, otherwise 0
var iNum1 =; // 25 equals 0000 0000 0000 0000 0000 0000 0001 1001 var iNum2 = 3; // 3 equals 0000 0000 0000 0000 0000 0000 0000 0011Alert (iNum2); // output //1 equals 0000 0000 0000 0000 0000 0000 0000 0001
The bitwise operation or is represented by the symbol (|), and is directly the binary form of the number, all 0 is 0, otherwise 1
var iNum1 =; // 25 equals 0000 0000 0000 0000 0000 0000 0001 1001 var iNum2 = 3; // 3 equals 0000 0000 0000 0000 0000 0000 0000 0011Alert (iNum2); // output //27 equals 0000 0000 0000 0000 0000 0000 0001 1011
Bitwise operation XOR is represented by a symbol (^), and, of course, it is also performed directly on the binary form, with a difference of 1, the same as 0
var iNum1 =; // 25 equals 0000 0000 0000 0000 0000 0000 0001 1001 var iNum2 = 3; // 3 equals 0000 0000 0000 0000 0000 0000 0000 0011Alert (iNum2); // output //26 equals 0000 0000 0000 0000 0000 0000 0001 1010
The left shift operation is represented by a two less than sign (<<). It moves all digits in the number to the left by the specified number.
var iNum1 = 2; // equals binary ten var iNum2 = iNum1 << 5; // equals binary 10 million binary
Type conversion in JavaScript (binary conversion | bit operation)