Check out example codes for "transformer un string en double java". It will help you in understanding the concepts better.

Code Example 1

String s = "10.1";
Double d = Double.parseDouble(s);

Code Example 2

String number = "123,321";
double value = Double.parseDouble( number.replace(",",".") );

Code Example 3

double total = Double.parseDouble(jlbTotal.getText());
double price = Double.parseDouble(jlbPrice.getText());

Code Example 4

String doubleAsString = "23.23";
BigDecimal price = new BigDecimal(doubleAsString);
BigDecimal total = price.plus(anotherPrice);

Code Example 5

String text = "12.34"; // example String
double value = Double.parseDouble(text);

Code Example 6

double d = Double.parseDouble(aString);

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