?? (Nullish Coalescing)
?? (Nullish Coalescing) is a JavaScript function in the Operators category. Returns b if a is null/undefined. The syntax is a ?? b. A typical example: null ?? "default" // "default". A close sibling is + (Addition), which adds numbers or concatenates strings. A close sibling is - (Subtraction), which subtracts numbers. A close sibling is * (Multiplication), which multiplies numbers. A close sibling is === (Strict Equality), which strict equality. More about this category: Arithmetic, comparison, logical, bitwise operators. Related Operators methods: + (Addition), - (Subtraction), * (Multiplication), === (Strict Equality), && (Logical AND), || (Logical OR), ?. (Optional Chaining), typeof. This page is part of the free JS Reference documentation covering 1027+ methods, each with syntax, parameters, return values, examples, and common pitfalls. You can try ?? (Nullish Coalescing) immediately in the JavaScript playground, look up unfamiliar terms in the glossary, or return to the JS Reference homepage.