p5.js Table getString()用法及代码示例

p5.js中p5.Table的getString()方法用于从表的给定行和列中检索String值。可以通过行ID来指定行，并且可以通过其列ID或列名来指定列。

用法:

getString( row, column )

参数：此方法接受上面提到和下面描述的两个参数：

row:该数字表示行的行ID。
column:它是一个字符串或数字，表示列的名称或列的ID。

返回值：此方法返回一个String，它是从表的给定行和列中检索到的值。

以下示例说明了p5.js中的getString()方法：

范例1：

Javascript

function setup() { 
  createCanvas(600, 300); 
  textSize(18); 
  
  text("Click on the button to get all " + 
  "string values of the table", 20, 20); 
  
  setBtn = 
    createButton("Get all table values"); 
  setBtn.position(30, 40); 
  setBtn.mouseClicked(showTable); 
  
  // Create the table 
  table = new p5.Table(); 
  
  setTableData(); 
} 
  
function setTableData() { 
  table.addColumn('Waterfall'); 
  table.addColumn('Height'); 
  
  let tableRow = table.addRow(); 
  tableRow.setString('Waterfall', 
                     'Angel Falls'); 
  tableRow.setString('Height', 
                     '979 metres'); 
  
  tableRow = table.addRow(); 
  tableRow.setString('Waterfall', 'Tugela Falls'); 
  tableRow.setString('Height', '948 metres'); 
  
  tableRow = table.addRow(); 
  tableRow.setString('Waterfall', 'Tres Hermanas Falls'); 
  tableRow.setString('Height', '914 metres'); 
} 
  
function showTable() { 
  clear(); 
  text("The values of the table are retrieved " + 
  "using the getString() method", 20, 20); 
  
  // Show all the columns present 
  for (let c = 0; c < table.getColumnCount(); c++) { 
    text(table.columns, 20 + 200 * c, 80); 
  } 
  
  // Show all the rows currently 
  // present in the table 
  for (let r = 0; r < table.getRowCount(); r++) { 
    for (let c = 0; c < table.getColumnCount(); c++) { 
  
      // Get the string at the given row and column 
      text(table.getString(r, c), 
           20 + 200 * c, 
           110 + 20 * r); 
    } 
  } 
}

输出：

范例2：

Javascript

function setup() { 
  createCanvas(600, 300); 
  textSize(18); 
  
  text("Click on the button to get the " + 
       "specific string value of the table", 
       20, 20); 
  
  text("Enter row and column", 20, 60); 
  
  rowInp = createInput(); 
  rowInp.position(30, 80); 
  rowInp.size(30, 20); 
  
  colInp = createInput(); 
  colInp.position(70, 80); 
  colInp.size(30, 20); 
  
  setBtn = 
    createButton("Get value at row and column"); 
  setBtn.position(30, 110); 
  setBtn.mouseClicked(getValueAt); 
  
  // Create the table 
  table = new p5.Table(); 
  
  setTableData() 
} 
  
function setTableData() { 
  
  table.addColumn('Waterfall'); 
  table.addColumn('Height'); 
  
  let tableRow = table.addRow(); 
  tableRow.setString('Waterfall', 'Angel Falls'); 
  tableRow.setString('Height', '979 metres'); 
  
  tableRow = table.addRow(); 
  tableRow.setString('Waterfall', 'Tugela Falls'); 
  tableRow.setString('Height', '948 metres'); 
  
  tableRow = table.addRow(); 
  tableRow.setString('Waterfall', 'Tres Hermanas Falls'); 
  tableRow.setString('Height', '914 metres'); 
  
} 
  
function getValueAt() { 
  clear(); 
  let rowToGet = int(rowInp.value()); 
  let colToGet = int(colInp.value()); 
  
  if (rowToGet < table.getRowCount() && 
      colToGet < table.getColumnCount()) { 
    text("The value at row " + rowToGet + 
         " and column " + colToGet + " is:", 
         20, 160); 
  
    // Get the string at the given row and column 
    text(table.getString(rowToGet, colToGet), 
         20, 180); 
  } 
  else
    text("Please enter correct row and " + 
         "column values", 20, 160); 
  
  
  text("Click on the button to get the " + 
       "specific string value of the table", 
       20, 20); 
  text("Enter row and column", 20, 60); 
}

输出：

在线编辑： https://editor.p5js.org/

环境设置： https://www.geeksforgeeks.org/p5-js-soundfile-object-installation-and-methods/

参考： https://p5js.org/reference/#/p5.Table/getString

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注：本文由纯净天空筛选整理自sayantanm19大神的英文原创作品 p5.Table getString() Method。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。