1Mathematics A significant zero in the decimal representation of a number.
〔数〕有效零
Example sentencesExamples
The use of zero as a placeholder was probably first developed by the Babylonians, possibly as early as 1500 BCE.
It emphasises the use of zero as a placeholder.
1.1A symbol or piece of text used in a mathematical expression or in an instruction in a computer program to denote a missing quantity or operator.
占位符号
Example sentencesExamples
Notice how we use DBI's placeholders, shown here as a question mark in the list of VALUES, to avoid potential problems with quoted strings within our SQL query.
Not only does this reduce the risk of someone messing with our SQL, but some database drivers will take advantage of our placeholders in subsequent queries, giving us a speed boost.
But even users of low-end databases can benefit from using placeholders because they ensure strings will be quoted correctly, even if they contain quotation marks or apostrophes.
The HTML files contain placeholders for data that will be substituted in at runtime.
With the Impress files created, I needed to replace my graphic image placeholders with the actual image.
2Linguistics An element of a sentence that is required by syntactic constraints but carries little or no semantic information, for example the word it as a subject in it is a pity that she left, where the true subject is that she left.
〔语言学〕占位成分，形式主语，形式宾语（句法规则要求，但又没有语义信息的句子成分，例如：it is a pity that she left一句中的主语it，that she left才是真正的主语）
Example sentencesExamples
The it in suffice it to say is an impersonal or indefinite pronoun, one that functions as a grammatical placeholder without supplying much real meaning.
According to this model, readers process text in parallel at several levels of analysis, which mesh the ease of identification with the role of function words as structural placeholders.
Definition of placeholder in US English:
placeholder
nounˈpleɪsˌhoʊldərˈplāsˌhōldər
1Mathematics A significant zero in the decimal representation of a number.
〔数〕有效零
Example sentencesExamples
The use of zero as a placeholder was probably first developed by the Babylonians, possibly as early as 1500 BCE.
It emphasises the use of zero as a placeholder.
1.1A symbol or piece of text used in a mathematical expression or in an instruction in a computer program to denote a missing quantity or operator.
占位符号
Example sentencesExamples
Not only does this reduce the risk of someone messing with our SQL, but some database drivers will take advantage of our placeholders in subsequent queries, giving us a speed boost.
But even users of low-end databases can benefit from using placeholders because they ensure strings will be quoted correctly, even if they contain quotation marks or apostrophes.
With the Impress files created, I needed to replace my graphic image placeholders with the actual image.
Notice how we use DBI's placeholders, shown here as a question mark in the list of VALUES, to avoid potential problems with quoted strings within our SQL query.
The HTML files contain placeholders for data that will be substituted in at runtime.
2Linguistics An element of a sentence that is required by syntactic constraints but carries little or no semantic information, for example the word it as a subject in it is a pity that she left, where the true subject is that she left.
〔语言学〕占位成分，形式主语，形式宾语（句法规则要求，但又没有语义信息的句子成分，例如：it is a pity that she left一句中的主语it，that she left才是真正的主语）
Example sentencesExamples
The it in suffice it to say is an impersonal or indefinite pronoun, one that functions as a grammatical placeholder without supplying much real meaning.
According to this model, readers process text in parallel at several levels of analysis, which mesh the ease of identification with the role of function words as structural placeholders.