Word · Frequency #12712
null
空值；无；零
An empty or non-existent value; nothing; in computing, the absence of a value.
计算机和数据库中常指空值；一般可理解为“没/无/零”。
- 1.
A non-existent or empty value or set of values.
不存在或空的值或值集
- 2.
Zero quantity of expressions; nothing.
零数量的表达式；无
- 3.
Something that has no force or meaning.
无效或无意义的事物
- 4.
The null character; the ASCII or Unicode character (␀), represented by a zero value, which indicates no character and is sometimes used as a string terminator.
空字符；ASCII或Unicode字符(␀),值为零,表示无字符,有时用作字符串终止符
- 5.
The attribute of an entity that has no valid value.
实体没有有效值的属性
- 6.
One of the beads in nulled work.
空花工艺中的珠子之一
- 7.
The null hypothesis.
零假设
零假设；原假设；空字符；无效之物；无意义之物；珠形饰；不存在或空的值或值集
In use
The database query returned a null for the missing field.
He initialized the pointer as null to indicate it points to nothing.
After the deletion operation, the array contained several nulls.
assign sth to null
The programmer assigned the variable to null.
程序员将变量赋值为空。
return null
The function returns null if the input is invalid.
如果输入无效，函数返回空。
check for null
Always check for null before using a pointer.
Connections
Collocations
- null value
- 空值
- If the field contains a null value, the program skips it.如果字段包含空值，程序会跳过它。
- null character
- 空字符
- C strings end with a null character.C 语言字符串以空字符结尾。
- null pointer
- 空指针
- Check for a null pointer before you use it.使用前先检查空指针。
- null check
- 空值检查
- Always do a null check before accessing the object.在访问该对象之前，务必进行空值检查。
- return null
- 返回空值
- The function returns null if no match is found.如果找不到匹配项，该函数返回空值。
Synonyms
Learner notes
Memory Tip
可这样记：null 像数字 0 两边各站一条竖线（两个 l），表示空无所有——空值、零、无意义。
Context & Register
语域：neutral 常见场景：编程、数据库、数据处理 表示“空值、无值”时，多用于计算机编程和数据处理领域，属于中性而偏专业的说法；在日常口语中较少单独使用。
Grammar Note
常用于法律和计算机语境，表示无效或空值。
Pronunciation & Spelling
All listed words share the vowel sound /ʌ/ and the ending /l/, spelled '-ull', and rhyme with null. No common lookalikes with different pronunciation exist for this set.
Learn the forms together
页面下方列出了常见词形变化。学习时注意它们在句子中的语法位置。
Dictionary facts from ECDICT, WIKTIONARY, WORDNET.