If radix is omitted, JavaScript assumes radix 10. If the value begins with "0x", JavaScript assumes radix 16.
Notes
If the first character cannot be converted, NaN
is returned.
Leading and trailing spaces are ignored.
Only the first integer found is returned.
Older browsers will return 8 for parseInt["010"]. Older versions of ECMAScript used octal [radix 8] for values beginning with "0". From ECMAScript 5 [2009] default is decimal [radix 10].
Integer.parseInt[]: While operating upon strings, there are times when we need to convert a number represented as a string into an integer type. The method generally used to convert String to Integer in Java is parseInt[]. This method belongs to Integer class in java.lang package. It takes a valid string as a parameter and parses it into primitive data type int. It only accepts String as a parameter and on passing values of any other data type, it produces an error due to incompatible types. There are two variants of this method:
Syntax:
public static int parseInt[String s] throws NumberFormatException
public static int parseInt[String s, int radix] throws NumberFormatException
Example:
Java
public
public static int parseInt[String s, int radix] throws NumberFormatException
0
public static int parseInt[String s, int radix] throws NumberFormatException
1
public static int parseInt[String s, int radix] throws NumberFormatException
2`public`
public static int parseInt[String s, int radix] throws NumberFormatException
4
public static int parseInt[String s, int radix] throws NumberFormatException
5
public static int parseInt[String s, int radix] throws NumberFormatException
6
public static int parseInt[String s, int radix] throws NumberFormatException
2
public static int parseInt[String s, int radix] throws NumberFormatException
8
public static int parseInt[String s, int radix] throws NumberFormatException
9
20 20 -20 32 11670324
0
20 20 -20 32 11670324
1
20 20 -20 32 11670324
2
20 20 -20 32 11670324
3
public static int parseInt[String s, int radix] throws NumberFormatException
9
20 20 -20 32 11670324
0
20 20 -20 32 11670324
6
20 20 -20 32 11670324
2
20 20 -20 32 11670324
3
public static int parseInt[String s, int radix] throws NumberFormatException
9
20 20 -20 32 11670324
0
public static Integer valueOf[int a]
1
20 20 -20 32 11670324
2
20 20 -20 32 11670324
3
public static int parseInt[String s, int radix] throws NumberFormatException
9
20 20 -20 32 11670324
0
public static Integer valueOf[int a]
6
20 20 -20 32 11670324
2
public static Integer valueOf[int a]
8
public static Integer valueOf[int a]
9
public static Integer valueOf[String str]
0
public static int parseInt[String s, int radix] throws NumberFormatException
9
20 20 -20 32 11670324
0
public static Integer valueOf[String str]
3
public static Integer valueOf[String str]
4
public static Integer valueOf[String str]
0
public static int parseInt[String s, int radix] throws NumberFormatException
9
public static Integer valueOf[String str]
7
public static int parseInt[String s, int radix] throws NumberFormatException
9
public static Integer valueOf[String str]
9
public static int parseInt[String s, int radix] throws NumberFormatException
9
public static Integer valueOf[String str, int base]
1
public static int parseInt[String s, int radix] throws NumberFormatException
9
public static Integer valueOf[String str, int base]
3
public static int parseInt[String s, int radix] throws NumberFormatException
9
public static Integer valueOf[String str, int base]
5
public static int parseInt[String s, int radix] throws NumberFormatException
2
public static Integer valueOf[String str, int base]
7
public static Integer valueOf[String str, int base]
7
Output:
20 20 -20 32 11670324
Integer.valueOf[]: This method is a static method belonging to the java.lang package which returns the relevant Integer Object holding the value of the argument passed. This method can take an integer or a String as a parameter. But when the given String is invalid, it provides an error. This method can also take in a character as a parameter but the output will be its corresponding Unicode value. This method will always cache values in the range -128 to 127, inclusive, and may cache other values outside of this range. Syntax:
public static Integer valueOf[int a]
public static Integer valueOf[String str]
public static Integer valueOf[String str, int base]
Example:
Java
public static Integer valueOf[String str, int base]
9
Output Value = 85
0
public
public static int parseInt[String s, int radix] throws NumberFormatException
0
Output Value = 85
3
public static int parseInt[String s, int radix] throws NumberFormatException
2`public`
public static int parseInt[String s, int radix] throws NumberFormatException
4
public static int parseInt[String s, int radix] throws NumberFormatException
5
Output Value = 85
8
public static int parseInt[String s, int radix] throws NumberFormatException
2
public static int parseInt[String s, int radix] throws NumberFormatException
8
public static int parseInt[String s, int radix] throws NumberFormatException
9
prog.java:18: error: incompatible types: int cannot be converted to String
int str = Integer.parseInt[val];
^
1 error2
prog.java:18: error: incompatible types: int cannot be converted to String
int str = Integer.parseInt[val];
^
1 error3
prog.java:18: error: incompatible types: int cannot be converted to String
int str = Integer.parseInt[val];
^
1 error4
prog.java:18: error: incompatible types: int cannot be converted to String
int str = Integer.parseInt[val];
^
1 error5
public static Integer valueOf[String str]
0
public static int parseInt[String s, int radix] throws NumberFormatException
9
prog.java:18: error: incompatible types: int cannot be converted to String
int str = Integer.parseInt[val];
^
1 error8
prog.java:18: error: incompatible types: int cannot be converted to String
int str = Integer.parseInt[val];
^
1 error9
prog.java:18: error: incompatible types: char cannot be converted to String
int str = Integer.parseInt[val];
^
1 error0
prog.java:18: error: incompatible types: char cannot be converted to String
int str = Integer.parseInt[val];
^
1 error1
prog.java:18: error: incompatible types: char cannot be converted to String
int str = Integer.parseInt[val];
^
1 error2
public static int parseInt[String s, int radix] throws NumberFormatException
2
public static Integer valueOf[String str, int base]
7
public static Integer valueOf[String str, int base]
7
Output:
Output Value = 85
Differences between Integer.parseInt[] and Integer.valueOf[]
- Integer.valueOf[] returns an Integer object while Integer.parseInt[] returns a primitive int.
Java
public static int parseInt[String s, int radix] throws NumberFormatException
0
prog.java:18: error: incompatible types: char cannot be converted to String
int str = Integer.parseInt[val];
^
1 error7
public static int parseInt[String s, int radix] throws NumberFormatException
2`public`
public static int parseInt[String s, int radix] throws NumberFormatException
4
public static int parseInt[String s, int radix] throws NumberFormatException
5
public static int parseInt[String s, int radix] throws NumberFormatException
6
public static int parseInt[String s, int radix] throws NumberFormatException
2
public static int parseInt[String s, int radix] throws NumberFormatException
8
public static int parseInt[String s, int radix] throws NumberFormatException
9`public`6`public`7`public`8
public static int parseInt[String s, int radix] throws NumberFormatException
9
20 20 -20 32 11670324
0
public static int parseInt[String s, int radix] throws NumberFormatException
01
public static int parseInt[String s, int radix] throws NumberFormatException
9
public static int parseInt[String s, int radix] throws NumberFormatException
03
public static int parseInt[String s, int radix] throws NumberFormatException
9
20 20 -20 32 11670324
0
public static int parseInt[String s, int radix] throws NumberFormatException
06
public static int parseInt[String s, int radix] throws NumberFormatException
9
public static int parseInt[String s, int radix] throws NumberFormatException
08
public static int parseInt[String s, int radix] throws NumberFormatException
2
public static Integer valueOf[String str, int base]
7
public static Integer valueOf[String str, int base]
7
- Both String and integer can be passed a parameter to Integer.valueOf[] whereas only a String can be passed as parameter to Integer.parseInt[].
Java
public static int parseInt[String s, int radix] throws NumberFormatException
0
public static int parseInt[String s, int radix] throws NumberFormatException
13
public static int parseInt[String s, int radix] throws NumberFormatException
2`public`
public static int parseInt[String s, int radix] throws NumberFormatException
4
public static int parseInt[String s, int radix] throws NumberFormatException
5
public static int parseInt[String s, int radix] throws NumberFormatException
6
public static int parseInt[String s, int radix] throws NumberFormatException
2
public static int parseInt[String s, int radix] throws NumberFormatException
8
public static int parseInt[String s, int radix] throws NumberFormatException
9
20 20 -20 32 11670324
0
public static int parseInt[String s, int radix] throws NumberFormatException
23
public static int parseInt[String s, int radix] throws NumberFormatException
24
public static int parseInt[String s, int radix] throws NumberFormatException
25
public static int parseInt[String s, int radix] throws NumberFormatException
9
public static int parseInt[String s, int radix] throws NumberFormatException
27
public static int parseInt[String s, int radix] throws NumberFormatException
8
public static int parseInt[String s, int radix] throws NumberFormatException
29
20 20 -20 32 11670324
0
public static int parseInt[String s, int radix] throws NumberFormatException
31
public static int parseInt[String s, int radix] throws NumberFormatException
29
public static int parseInt[String s, int radix] throws NumberFormatException
08
public static int parseInt[String s, int radix] throws NumberFormatException
29
20 20 -20 32 11670324
0
public static int parseInt[String s, int radix] throws NumberFormatException
36
public static int parseInt[String s, int radix] throws NumberFormatException
29
public static int parseInt[String s, int radix] throws NumberFormatException
03
public static int parseInt[String s, int radix] throws NumberFormatException
9
public static Integer valueOf[String str, int base]
7
public static int parseInt[String s, int radix] throws NumberFormatException
9
public static int parseInt[String s, int radix] throws NumberFormatException
42
public static int parseInt[String s, int radix] throws NumberFormatException
43
public static int parseInt[String s, int radix] throws NumberFormatException
29
public static int parseInt[String s, int radix] throws NumberFormatException
45
public static int parseInt[String s, int radix] throws NumberFormatException
9
public static Integer valueOf[String str, int base]
7
public static int parseInt[String s, int radix] throws NumberFormatException
2
public static Integer valueOf[String str, int base]
7
public static Integer valueOf[String str, int base]
7
- Compilation Error:
prog.java:18: error: incompatible types: int cannot be converted to String
int str = Integer.parseInt[val];
^
1 error- Integer.valueOf[] can take a character as parameter and will return its corresponding unicode value whereas Integer.parseInt[] will produce an error on passing a character as parameter.
Java
public static int parseInt[String s, int radix] throws NumberFormatException
0
public static int parseInt[String s, int radix] throws NumberFormatException
13
public static int parseInt[String s, int radix] throws NumberFormatException
2`public`
public static int parseInt[String s, int radix] throws NumberFormatException
4
public static int parseInt[String s, int radix] throws NumberFormatException
5
public static int parseInt[String s, int radix] throws NumberFormatException
6
public static int parseInt[String s, int radix] throws NumberFormatException
2
public static int parseInt[String s, int radix] throws NumberFormatException
8
public static int parseInt[String s, int radix] throws NumberFormatException
9
public static int parseInt[String s, int radix] throws NumberFormatException
61
public static int parseInt[String s, int radix] throws NumberFormatException
23
public static int parseInt[String s, int radix] throws NumberFormatException
63
public static int parseInt[String s, int radix] throws NumberFormatException
25
public static int parseInt[String s, int radix] throws NumberFormatException
9
public static int parseInt[String s, int radix] throws NumberFormatException
27
public static int parseInt[String s, int radix] throws NumberFormatException
8
public static int parseInt[String s, int radix] throws NumberFormatException
29
20 20 -20 32 11670324
0
public static int parseInt[String s, int radix] throws NumberFormatException
31
public static int parseInt[String s, int radix] throws NumberFormatException
29
public static int parseInt[String s, int radix] throws NumberFormatException
08
public static int parseInt[String s, int radix] throws NumberFormatException
29
20 20 -20 32 11670324
0
public static int parseInt[String s, int radix] throws NumberFormatException
36
public static int parseInt[String s, int radix] throws NumberFormatException
29
public static int parseInt[String s, int radix] throws NumberFormatException
03
public static int parseInt[String s, int radix] throws NumberFormatException
9
public static Integer valueOf[String str, int base]
7
public static int parseInt[String s, int radix] throws NumberFormatException
9
public static int parseInt[String s, int radix] throws NumberFormatException
42
public static int parseInt[String s, int radix] throws NumberFormatException
43
public static int parseInt[String s, int radix] throws NumberFormatException
29
public static int parseInt[String s, int radix] throws NumberFormatException
45
public static int parseInt[String s, int radix] throws NumberFormatException
9
public static Integer valueOf[String str, int base]
7
public static int parseInt[String s, int radix] throws NumberFormatException
2
public static Integer valueOf[String str, int base]
7
public static Integer valueOf[String str, int base]
7
- Compilation Error:
prog.java:18: error: incompatible types: char cannot be converted to String
int str = Integer.parseInt[val];
^
1 errorTable of difference
Integer.parseInt[] Integer.valueOf[] It can only take a String as a parameter. It can take a String as well as an integer as parameter. It returns a primitive int value. It returns an Integer object. When an integer is passed as parameter, it produces an error due to incompatible types When an integer is passed as parameter, it returns an Integer object corresponding to the given parameter. This method produces an error[incompatible types] when a character is passed as parameter. This method can take a character as parameter and will return the corresponding unicode. This lags behind in terms of performance since parsing a string takes a lot of time when compared to generating one. This method is likely to yield significantly better space and time performance by caching frequently requested values. If we need the primitive int datatype then Integer.parseInt[] method is to be used. If Wrapper Integer object is needed then valueOf[] method is to be used.
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