What is the expected result when the following script is run in the browser? In a script where a global variable v1 is initially set to 'Blue', a function assigns this.v1 = 'Green' and is invoked, followed by alert(v1). What is the outcome of running the script?

• A. Two alert boxes displaying Blue
• B. Two alert boxes, both displaying Green
• C. One alert with Green
• D. No alerts

Answer: (B)

Global variables are properties of the browser’s global object (window). When a global variable v1 is initially set to 'Blue', it becomes window.v1. Inside a function, this refers to the global object in non-strict mode, so this.v1 = 'Green' updates the same property, making v1 now 'Green'. If the function alerts v1 after that change, it will show Green, and the subsequent alert outside the function will also show Green. So you end up with two alerts, both displaying Green.