What does console.log('10' - '4', '10' + '4') output?

Console output

Why

With two string operands, - still forces numeric coercion because subtraction has no string form, so "10" - "4" is 10 - 4 = 6. The + operator, however, treats strings as strings and concatenates "10" + "4" into "104". One operator computes, the other glues. This is the core asymmetry of + versus the other arithmetic operators.