语法
参数
描述
name1
(必需) 第一个要分配的变量名称。 必须以字母开头。 不能是公式的输出结果或与区域的语法冲突。
name_value1
(必需) 分配给name1的值。
calculation_or_name2
(必需) 以下之一： 使用LET函数中名称和值组成的最终计算表达式。 这必须是LET函数中的最后一个参数。或者是第二次要分配给第二个name_value2键值对的名称。如果指定了名称，则name_value2 以及 calculator_or_name3是必选的。
name_value2
(可选) 分配给calculation_or_name2的值。
calculation_or_name3
(可选) 以下之一： 使用LET函数中所有名称的计算表达式。 LET函数中的最后一个参数必须是计算表达式。第三次要分配给第三个name_value3键值对的名称。 如果指定了名称，则name_value3 以及 calculator_or_name4是必选的。
使用说明
LET函数旨在公式中声明变量来更加容易地编写更复杂的公式。 命名变量后，可以为其分配静态值或基于计算的值。 这样，公式就可以根据需要来多次使用名称来引用变量，而变量的名称只能被分配一次。
优势
提升了性能
如果您在公式中多次写入相同的表达式，则Excel将多次计算该结果。而LET函数允许您按名称调用表达式，并且只让Excel计算一次。
易于阅读和编写
无需记住特定区域或单元格的引用指的是什么，您的计算表达式需要做的只有复制、粘贴表达式。 通过声明和命名变量的功能，您可以为自己和公式的使用者提供有意义的上下文。
遍历
LET函数非常方便进行遍历。其中的局部变量将充当“每个元素”。
但是您需要通过spread.options.allowDynamicArray = true;切换至动态数组模式
window.onload = function() {
var spread = new GC.Spread.Sheets.Workbook(_getElementById("ss"));
spread.options.allowDynamicArray = true;
initStyles(spread);
initSpread(spread);
};
function initSpread(spread) {
spread.setSheetCount(5);
spread.suspendPaint();
spread.suspendCalcService();
initSheet1(spread.getSheet(0));
initSheet2(spread.getSheet(1));
initSheet3(spread.getSheet(2));
initSheet4(spread.getSheet(3));
initSheet5(spread.getSheet(4));
spread.resumeCalcService();
spread.resumePaint();
}
function initStyles(spread) {
var introStyle = new GC.Spread.Sheets.Style();
introStyle.name = 'intro';
introStyle.font = 'normal bold 16px Segoe UI';
introStyle.foreColor = "#172b4d";
spread.addNamedStyle(introStyle);
var introSecStyle = new GC.Spread.Sheets.Style();
introSecStyle.name = 'introSec';
introSecStyle.font = 'normal bold 12px Segoe UI';
introSecStyle.foreColor = "#000";
spread.addNamedStyle(introSecStyle);
var introGrayStyle = new GC.Spread.Sheets.Style();
introGrayStyle.name = 'introGray';
introGrayStyle.font = 'normal bold 12px Segoe UI';
introGrayStyle.foreColor = "gray";
spread.addNamedStyle(introGrayStyle);
var introStyle1 = new GC.Spread.Sheets.Style();
introStyle1.name = 'intro1';
introStyle1.font = 'normal bold 14px Calibri';
introStyle1.hAlign = 0;
introStyle1.vAlign = 1;
introStyle1.foreColor = "#172b4d";
spread.addNamedStyle(introStyle1);
var formulaStyle = new GC.Spread.Sheets.Style();
formulaStyle.name = 'formula';
formulaStyle.font = 'normal bold 12px Consolas';
formulaStyle.foreColor = "#c00000";
introStyle1.vAlign = 1;
spread.addNamedStyle(formulaStyle);
var tableHeaderStyle = new GC.Spread.Sheets.Style();
tableHeaderStyle.name = 'tableHeader';
tableHeaderStyle.font = "normal bold 14.7px Calibri";
tableHeaderStyle.hAlign = 1;
tableHeaderStyle.backColor = "#d9e1f2";
spread.addNamedStyle(tableHeaderStyle);
var tableContentStyle = new GC.Spread.Sheets.Style();
tableContentStyle.name = 'tableContent';
tableContentStyle.font = "normal normal 14.7px Calibri";
tableContentStyle.hAlign = 1;
spread.addNamedStyle(tableContentStyle);
var sourceStyle = new GC.Spread.Sheets.Style();
sourceStyle.name = 'source';
sourceStyle.hAlign = 0;
sourceStyle.backColor = "#fce8ce";
spread.addNamedStyle(sourceStyle);
var resultStyle = new GC.Spread.Sheets.Style();
resultStyle.name = 'result';
resultStyle.hAlign = 0;
resultStyle.backColor = "#e2efda";
spread.addNamedStyle(resultStyle);
}
function initSheet1(sheet) {
sheet.name('Use Case');
var table1Source = {
name: 'Support Engineer Employment Length',
data: [
{ engineer: 'Bob', start: new Date(2014,4,25), salary: 2790 },
{ engineer: 'Jim', start: new Date(2019,6,20), salary: 2216 },
{ engineer: 'Kevin', start: new Date(2017,2,1), salary: 2498 },
{ engineer: 'Sarah', start: new Date(2020,6,14), salary: 1989 }
]
};
sheet.addSpan(1, 1, 1, 4);
sheet.setValue(1, 1, table1Source.name);
sheet.getCell(1, 1).hAlign(1).font("normal bold 15px Calibri");
sheet.setColumnWidth(1, 132);
sheet.setColumnWidth(2, 87);
sheet.setColumnWidth(3, 147);
sheet.setColumnWidth(4, 63);
var table1 = sheet.tables.add('Table1', 2, 1, 5, 4);
table1.style(GC.Spread.Sheets.Tables.TableThemes.medium7);
var table1Column1 = new GC.Spread.Sheets.Tables.TableColumn(1, "engineer", "Support Engineer");
var table1Column2 = new GC.Spread.Sheets.Tables.TableColumn(2, "start", "Start Date");
var table1Column3 = new GC.Spread.Sheets.Tables.TableColumn(3, null, "Time with Company");
var table1Column4 = new GC.Spread.Sheets.Tables.TableColumn(4, "salary", "Salary");
table1.autoGenerateColumns(false);
table1.bind([table1Column1, table1Column2, table1Column3, table1Column4], 'data', table1Source);
table1.setColumnDataFormula(2, '=LET(time,(YEAR(TODAY())-YEAR([@[Start Date]])),SWITCH(TRUE,time>5,"5+ years",time>=1,"1-4 years",time=0,"<= 1 Year"))');
var style = new GC.Spread.Sheets.Style();
style.backColor = 'rgb(112,173,71)';
style.foreColor = 'rgb(255,255,255)';
style.font = 'normal bold 14px Calibri';
sheet.setStyle(8, 1, style);
sheet.setValue(8, 1, 'Salary Calculations');
sheet.getCell(8, 2).backColor('rgb(227,239,218)');
sheet.getCell(8, 3).backColor('rgb(227,239,218)');
var lineStyle = GC.Spread.Sheets.LineStyle.dotted;
var lineBorder = new GC.Spread.Sheets.LineBorder('rgb(143,193,104)', lineStyle);
var sheetArea = GC.Spread.Sheets.SheetArea.viewport;
sheet.getRange(8, 1, 1, 3).setBorder(lineBorder, { left: true, right: true, top: true, bottom: true }, sheetArea);
var combo = new GC.Spread.Sheets.CellTypes.ComboBox();
combo.editorValueType(GC.Spread.Sheets.CellTypes.EditorValueType.value);
combo.items([
{ text: 'Min', value: 1 },
{ text: 'Max', value: 2 },
{ text: 'Average', value: 3 }
]);
sheet.setCellType(8, 2, combo, GC.Spread.Sheets.SheetArea.viewport);
sheet.setValue(8, 2, 3);
sheet.setFormula(8, 3, '=LET(data,Table1[Salary],calc,C9,aggregate,CHOOSE(calc,5,4,1),SUBTOTAL(aggregate, data))');
}
function initSheet2(sheet) {
sheet.name('#1');
sheet.setValue(1, 1, 'LET basic usage');
sheet.setStyle(1, 1, 'intro');
// Sample pair varible
var formula = '=LET(x,2,x+3)';
sheet.setValue(3, 1, 'Sample pair varible');
sheet.setStyle(3, 1, 'introSec');
sheet.setValue(4, 1, formula);
sheet.setStyle(4, 1, 'formula');
sheet.setValue(5, 1, 'Result');
sheet.setStyle(5, 1, 'result');
sheet.setFormula(5, 2, formula);
// Multiple pair varibles
var formula = '=LET(x,1,y,2,z,3,x+y+z=x*y*z)';
sheet.setValue(7, 1, 'Multiple pair varibles');
sheet.setStyle(7, 1, 'introSec');
sheet.setValue(8, 1, formula);
sheet.setStyle(8, 1, 'formula');
sheet.setValue(9, 1, 'Result');
sheet.setStyle(9, 1, 'result');
sheet.setFormula(9, 2, formula);
// Invoked formula
var formula = '=LET(x,1,y,2,SUM(x,y))';
sheet.setValue(11, 1, 'Invoked formula');
sheet.setStyle(11, 1, 'introSec');
sheet.setValue(12, 1, formula);
sheet.setStyle(12, 1, 'formula');
sheet.setValue(13, 1, 'Result');
sheet.setStyle(13, 1, 'result');
sheet.setFormula(13, 2, formula);
// Dynamic Array
var formula = '=LET(rows,0,cols,0,OFFSET(C18:E18,rows,cols))';
sheet.setValue(15, 1, 'Dynamic Array');
sheet.setStyle(15, 1, 'introSec');
sheet.setValue(16, 1, formula);
sheet.setStyle(16, 1, 'formula');
sheet.setValue(17, 1, 'Range');
sheet.setStyle(17, 1, 'source');
sheet.setArray(17, 2, [[1,2,3]]);
sheet.setValue(18, 1, 'Result');
sheet.setStyle(18, 1, 'result');
sheet.setFormula(18, 2, formula);
}
function initSheet3(sheet) {
sheet.name('#2');
sheet.setValue(1, 1, 'LET local varible & custom name');
sheet.setStyle(1, 1, 'intro');
sheet.setValue(2, 1, 'This sheet includes a custom name "user" which be assigned "Michael" value');
sheet.setStyle(2, 1, 'introGray');
sheet.addCustomName('user', '="Michael"');
sheet.setValue(3, 1, 'user');
sheet.setStyle(3, 1, 'source');
sheet.setFormula(3, 2, '=user');
// Always use let local varible first
var formula = '=LET(user,"Ivy","The actual user is: "&user)';
sheet.setValue(5, 1, 'Always use let local varible first');
sheet.setStyle(5, 1, 'introSec');
sheet.setValue(6, 1, formula);
sheet.setStyle(6, 1, 'formula');
sheet.setValue(7, 1, 'Result');
sheet.setStyle(7, 1, 'result');
sheet.setFormula(7, 2, formula);
// Use custom name if not avalible local varible
var formula = '=LET(user,user,"The actual user is: "&user)';
sheet.setValue(9, 1, 'Use custom name if not avalible local varible');
sheet.setStyle(9, 1, 'introSec');
sheet.setValue(10, 1, formula);
sheet.setStyle(10, 1, 'formula');
sheet.setValue(11, 1, 'Result');
sheet.setStyle(11, 1, 'result');
sheet.setFormula(11, 2, formula);
}
function initSheet4(sheet) {
sheet.name('#3');
sheet.setValue(1, 1, 'LET nested');
sheet.setStyle(1, 1, 'intro');
// Always use the current scope varible
var formula = '=LET(var,"First scope",LET(var,"Second scope",var))';
sheet.setValue(3, 1, 'Always use the current scope varible');
sheet.setStyle(3, 1, 'introSec');
sheet.setValue(4, 1, formula);
sheet.setStyle(4, 1, 'formula');
sheet.setValue(5, 1, 'Result');
sheet.setStyle(5, 1, 'result');
sheet.setFormula(5, 2, formula);
// Use the top scope varible if not found the avalible varible in current scope
var formula = '=LET(var,"First scope",LET(var,var,var&" [from the second scope]"))';
sheet.setValue(7, 1, 'Use the top scope varible if not found the avalible varible in current scope');
sheet.setStyle(7, 1, 'introSec');
sheet.setValue(8, 1, formula);
sheet.setStyle(8, 1, 'formula');
sheet.setValue(9, 1, 'Result');
sheet.setStyle(9, 1, 'result');
sheet.setFormula(9, 2, formula);
}
function initSheet5(sheet) {
sheet.name('#4');
sheet.setValue(1, 1, 'LET simplify the complex formula');
sheet.setStyle(1, 1, 'intro');
// Filter the data to show one person
var formula = '=LET(filterCriteria,H7,filteredRange,FILTER(B7:E13,B7:B13=filterCriteria),IF(ISBLANK(filteredRange),"-",filteredRange))';
sheet.setValue(3, 1, 'Filter the data to show one person');
sheet.setStyle(3, 1, 'introSec');
sheet.setValue(4, 1, formula);
sheet.setStyle(4, 1, 'formula');
var data = [
["Rep", "Region", "Product", "Profit"],
["Amy", "East", "Apple", 1.33 ],
["Fred", "South", "Banana", 0.09],
["Amy", "West", "Mango", 1.85],
["Fred", "North", null, 0.82],
["Fred", "West", "Banana", 1.25],
["Amy", "East", "Apple", 0.72],
["Fred", "North", "Mango", 0.54]
];
sheet.setStyle(5, 1, 'tableHeader');
sheet.setStyle(5, 2, 'tableHeader');
sheet.setStyle(5, 3, 'tableHeader');
sheet.setStyle(5, 4, 'tableHeader');
sheet.setArray(5, 1, data);
sheet.setValue(6, 6, 'Rep');
sheet.setStyle(6, 6, 'source');
sheet.setValue(7, 6, 'Result');
sheet.setStyle(7, 6, 'result');
sheet.setValue(6, 7, 'Fred');
sheet.setFormula(7, 7, formula);
// Generate all dates between May 1, 2020 and May 15, 2020
sheet.setColumnWidth(2, 72);
sheet.setColumnWidth(7, 72);
var formula = '=LET(dates,SEQUENCE(C19-C18+1,1,C18,1),FILTER(dates,WEEKDAY(dates,2)<6))';
var formatter = '[$-en-US]dd-mmm-yy;@';
sheet.setValue(15, 1, 'Generate all dates between May 1, 2020 and May 15, 2020');
sheet.setStyle(15, 1, 'introSec');
sheet.setValue(16, 1, formula);
sheet.setStyle(16, 1, 'formula');
sheet.setValue(17, 1, 'Start');
sheet.setStyle(17, 1, 'tableHeader');
sheet.setValue(18, 1, 'End');
sheet.setStyle(18, 1, 'tableHeader');
sheet.setValue(17, 2, new Date(2020, 4, 1));
sheet.setValue(18, 2, new Date(2020, 4, 15));
sheet.setFormatter(17, 2, formatter);
sheet.setFormatter(18, 2, formatter);
sheet.setValue(17, 6, 'Result');
sheet.setStyle(17, 6, 'result');
sheet.setFormula(17, 7, formula);
for (var i = 0; i < 11; i ++) {
sheet.setFormatter(i + 17, 7, formatter);
}
}
function _getElementById(id) {
return document.getElementById(id);
}
<!doctype html>
<html style="height:100%;font-size:14px;">
<head>
<meta charset="utf-8" />
<meta name="spreadjs culture" content="zh-cn" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<link rel="stylesheet" type="text/css"
href="$DEMOROOT$/zh/purejs/node_modules/@grapecity-software/spread-sheets/styles/gc.spread.sheets.excel2013white.css">
<script src="$DEMOROOT$/zh/purejs/node_modules/@grapecity-software/spread-sheets/dist/gc.spread.sheets.all.min.js"
type="text/javascript"></script>
<script src="$DEMOROOT$/spread/source/js/license.js" type="text/javascript"></script>
<script
src="$DEMOROOT$/zh/purejs/node_modules/@grapecity-software/spread-sheets-resources-zh/dist/gc.spread.sheets.resources.zh.min.js"
type="text/javascript"></script>
<script src="app.js" type="text/javascript"></script>
<link rel="stylesheet" type="text/css" href="styles.css">
</head>
<body>
<div class="sample-tutorial">
<div id="ss" class="sample-spreadsheets"></div>
</div>
</body>
</html>
input[type="text"] {
width: 200px;
margin-right: 20px;
}
label {
display: inline-block;
width: 110px;
}
.sample-tutorial {
position: relative;
height: 100%;
overflow: hidden;
}
.sample-spreadsheets {
width: 100%;
height: 100%;
overflow: hidden;
float: left;
}
label {
display: block;
margin-bottom: 6px;
}
input {
padding: 4px 6px;
}
input[type=button] {
margin-top: 6px;
display: block;
width:216px;
}
body {
position: absolute;
top: 0;
bottom: 0;
left: 0;
right: 0;
}
code {
border: 1px solid #000;
}
