How to convert String object to Boolean Object?

Question

How to convert String object to Boolean object?

Answer 1

Well, as now in Jan, 2018, the best way for this is to use apache's BooleanUtils.toBoolean.

This will convert any boolean like string to boolean, e.g. Y, yes, true, N, no, false, etc.

Really handy!

Answer 2

Visit http://msdn.microsoft.com/en-us/library/system.boolean.parse.aspx

This will give you an idea of what to do.

This is what I get from the Java documentation:

Method Detail

parseBoolean

public static boolean parseBoolean(String s)

Parses the string argument as a boolean. The boolean returned represents the value true if the string argument is not null and is equal, ignoring case, to the string "true".

Parameters:

s - the String containing the boolean representation to be parsed

Returns: the boolean represented by the string argument

Since: 1.5

Answer 3

Beside the excellent answer of KLE, we can also make something more flexible:

boolean b = string.equalsIgnoreCase("true") || string.equalsIgnoreCase("t") || 
        string.equalsIgnoreCase("yes") || string.equalsIgnoreCase("y") || 
        string.equalsIgnoreCase("sure") || string.equalsIgnoreCase("aye") || 
        string.equalsIgnoreCase("oui") || string.equalsIgnoreCase("vrai");

(inspired by zlajo's answer... :-))

Answer 4

Use the Apache Commons library BooleanUtils class:

String[] values= new String[]{"y","Y","n","N","Yes","YES","yes","no","No","NO","true","false","True","False","TRUE","FALSE",null};
for(String booleanStr : values){
    System.out.println("Str ="+ booleanStr +": boolean =" +BooleanUtils.toBoolean(booleanStr));
}

Result:

Str =N: boolean =false
Str =Yes: boolean =true
Str =YES: boolean =true
Str =yes: boolean =true
Str =no: boolean =false
Str =No: boolean =false
Str =NO: boolean =false
Str =true: boolean =true
Str =false: boolean =false
Str =True: boolean =true
Str =False: boolean =false
Str =TRUE: boolean =true
Str =FALSE: boolean =false
Str =null: boolean =false

Answer 5

To get the boolean value of a String, try this:

public boolean toBoolean(String s) {
    try {
        return Boolean.parseBoolean(s); // Successfully converted String to boolean
    } catch(Exception e) {
        return null; // There was some error, so return null.
    }
}

If there is an error, it will return null. Example:

toBoolean("true"); // Returns true
toBoolean("tr.u;e"); // Returns null

Answer 6

Boolean b = Boolean.valueOf(string);

The value of b is true if the string is not a null and equal to true (ignoring case).