Angela Yu Javascript May 2026

// The "Angela Yu" classic example: let result = "Angela" + " " + "Yu"; // "Angela Yu" - normal

// But then she shows the weird part: let weird = "Angela" - "Yu"; // NaN (Not a Number) let weird2 = "Angela" * 1; // NaN let weird3 = [] + []; // "" (empty string) let weird4 = [] + {}; // "[object Object]" let weird5 = {} + []; // 0 (in some consoles, due to {} being interpreted as a block) angela yu javascript

console.log([] + []); // "" console.log([] + {}); // "[object Object]" console.log({} + []); // 0 (in Chrome console) The circulating in forums and tweets is often phrased as: "Angela Yu once broke JavaScript by making it think 'Angela' minus 'Yu' equals 'Not a Number' – and then laughed while students questioned their life choices." So if someone says "Angela Yu JavaScript story" , they likely mean the type coercion horror story from her bootcamp that haunts beginners (and amuses veterans). // The "Angela Yu" classic example: let result

The actual she tells isn't about a narrative plot, but a teaching moment : She asks students to predict the output of: // 0 (in some consoles

This is a reference to a famous and rather terrifying (but educational) JavaScript story involving and her "JS is a weird language" lesson.