Tasting both sweet and salty at the same time; can also describe a bittersweet emotional nuance.
このポテトチップスは甘じょっぱくてつい手が伸びる。
These potato chips are sweet-and-salty and I can't stop reaching for them.
トマトソースに砂糖を少し入れると甘じょっぱい味になる。
Adding a little sugar to the tomato sauce makes it sweet-and-salty.
あの映画は甘じょっぱい青春の思い出を描いている。
That movie depicts bittersweet memories of youth.