删除"null"带有if语句的Leaflet弹出窗口中的属性 [英] Remove "null" attributes in Leaflet popups with an if-statement

问题描述

我正在使用外部geojson属性来填充Leaflet中的弹出窗口，如下所示:

I am using external geojson attributes to fill my popup windows in Leaflet, like this:

function popUp (feature, geojson) {
var popupText=
"/*Name:*/" + feature.properties.name  + 
"/*Amount*/" + feature.properties.amounts;
geojson.bindPopup(popupText);
};

问题:某些金额为"null".那么，如何编写if语句，以便如果金额为"null"，则字符串("Amount")和属性("null")都不会显示在弹出窗口中?

The problem: some of the amounts are "null". So, how do I write an if statement, so that if an amount is "null" then both the string ("Amount") and the attribute ("null") don't show up in the popup?

推荐答案

您要查找的是条件语句:

What you are looking for is a conditional statement:

https://developer. mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Statements/if...else

var popupText = '';

if (feature.properties.name) {
    popupText += '/*Name:*/' + feature.properties.name;
}

if (feature.properties.amount) {
    popupText += '/*Amount*/' + feature.properties.amount;
}

geojson.bindPopup(popupText);

或更短地使用条件三元运算符:

Or even shorter using a conditional ternary operator:

https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Operators/Conditional_Operator

var popupText = '';

popupText += (feature.properties.name) ? '/*Name:*/' + feature.properties.name : '';

popupText += (feature.properties.amount) ? '/*Amount*/' + feature.properties.amount : '';

geojson.bindPopup(popupText);

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