Table fixed column width and centering method in Latex

Table fixed column width and center
Method One:
In the introductory area:
\usepackage{array}
\newcolumntype{c}[1]{>{\centering}p{#1}}
In the table, if you need to set a fixed width of a column (assuming the column width is set to 5cm) and centered, the corresponding columnar definition should be set to c{5cm}
When using this method, the line breaks in the table cannot be used with \ \ or \newline, use \tabularnewline.
Method Two:
In the introductory area:
\usepackage{array}
\newcommand{\preservebackslash}[1]{\let\temp=\\ #1 \let\\=\temp}
\newcolumntype{c}[1]{>{\preservebackslash\centering}p{#1}}
\newcolumntype{r}[1]{>{\preservebackslash\raggedleft}p{#1}}
\newcolumntype{l}[1]{>{\preservebackslash\raggedright}p{#1}}
In the table, if you need to set a fixed width of a column (assuming the column width is set to 5cm) and centered, the corresponding columnar definition should be set to c{5cm};
If you need to set a fixed width of a column (assuming the column width is set to 5cm) and left, the corresponding columnar definition should be set to l{5cm};
If you need to set a fixed width of a column (assuming the column width is set to 5cm) and right, the corresponding columnar definition should be set to r{5cm};
Use this method to wrap lines in a table with \ \.
For more information, refer to the documentation for the array macro package.