Javascript,不带三元运算符的字符串连接

var myVar = 'myString is';
if (1===1){myVar+=' really true';}

我认为这比一行布尔测试更具可读性

myVar=“我的字符串是”+myHelper(…myParams);

你可以用 ||

myVar = (1 === 1 && "myString is really true") || "";

包装 1 === 1 && " really true" () 再加上 || '' 像下面这样(也用括号括起来),或者可以使用模板文本来节省您键入这些文本的时间 + s

let myString = "myString is" + ((1 === 1 && " really true") || '');
let myFalseString = "myString is" + ((1 === 0 && " really true") || '');
let onlyFalse = "myString is" + 1 === 1 && " really true";
let myTL = `myString is ${(1 === 1 && "really true") || ''}`;

console.log('My String:', myString);
console.log('False String:', myFalseString);
console.log('Only false:', onlyFalse);
console.log('My Template Literal:', myTL);

看起来比有多余的更糟 : "" 尽管如此,我还是建议这样做:

myVar = "myString is" + 1 === 1 ? " really true" : "";

: '' 但据我所知 : ''

console.log( ["my string is", 1 === 1 && "really true"].filter(Boolean).join(" ") );
console.log( ["my string is", 1 === 2 && "really true"].filter(Boolean).join(" ") );

: ''

function concat(){
  let str = "";
  for(let s of arguments){
    str += s ? s : '';
  }
  return str;
}

console.log( concat("my string is", 1 === 1 && "really true") );
console.log( concat("my string is", 1 === 2 && "really true") );

分析三元运算符,我们得出如下结论:

// Example: 1 === 1 ? ' is really true' : ''
if (1 === 1) {
    return ' is really true';
} else {
    return '';
}

if (1 === 1) {
    myVar += 'is really true';
}

使用逻辑运算符内联的最佳解决方案是三元运算符本身。它的“false”部分作为空字符串“”不是问题。但如果您真的对此感到恼火,您可以创建一个函数并使用如下模板文本:

function myFunction(evaluation) {
    if (evaluation) {
        return ' really true';
    }
    return '';
}

let myVar = `My String is ${myFunction(1 === 1)}`;