square bracket

A punctuation mark, either [ or ], used to enclose additional information, editorial comments, or technical notations in written text.

• 🇨🇳用于标示补充信息、编辑注释或技术标记的标点符号，成对使用，分为左方括号 [ 和右方括号 ]。

1. Punctuation mark B2 formal

   A pair of symbols [ ] used in writing to enclose additional information, corrections, or editorial comments.

   • The editor added a note in square brackets.
   • Use square brackets to indicate a change in a quotation.
   • The instructions said to put the answer in square brackets.

   🇨🇳方括号

2. Mathematical notation B2 formal

   Symbols used in mathematics to denote intervals, arrays, or to group expressions.

   • The interval [0, 1] includes all numbers between 0 and 1.
   • In the equation, the expression inside the square brackets is evaluated first.
   • Square brackets are used to denote matrices in linear algebra.

   🇨🇳方括号