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Commit a049cb0

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Ram swaroop

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Lines changed: 20 additions & 1 deletion

Original file line number	Diff line number	Diff line change
`@@ -303,8 +303,27 @@ solves the issue.`
`303`	`303`
`304`	`304`	`#### What happens when you cast a large value to store it in a small container`
`305`	`305`
	`306`	`+When you do a explicit cast, the compiler just keeps __the number of bits (from right)__ that the variable type can hold`
	`307`	`+and strips off the rest. Consider the below program to understand better:`
`306`	`308`
	`309`	`+{% highlight java linenos %}`
	`310`	`+class Casting {`
	`311`	`+ public static void main(String [] args) {`
	`312`	`+ int i = 7;`
	`313`	`+ byte b = (byte) i;`
	`314`	`+ System.out.println("The 1st byte is " + b); // prints 7`
	`315`	`+ // now let's see another example`
	`316`	`+ int i = 128;`
	`317`	`+ byte b = (byte) i;`
	`318`	`+ System.out.println("The 2nd byte is " + b); // prints -128`
	`319`	`+ }`
	`320`	`+}`
	`321`	`+{% endhighlight %}`
`307`	`322`
`308`		`-`
	`323`	+So, in line 4, `i` is `7` i.e, `00000000000000000000000000000111` (32 bits) and when we do a explicit cast, the compiler
	`324`	+just stores `00000111` (8 bits) in variable `b` (as `byte` can hold only 8 bits) which is also `7`. Therefore, it prints
	`325`	+`7`. But in line 8, `i` is `128` i.e, `00000000000000000000000010000000` and after stripping off the extra bits we are
	`326`	+left with `10000000` which is not `128` as the 1st bit is the sign bit. So, after computing the 2's compliment of it we
	`327`	+get `-128` as the result.
`309`	`328`
`310`	`329`

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