javascript - 正则表达式替换和追加字符串

Question

我设法删除了字符串中的每个“-xx”(示例 1)。我希望您能帮助示例 2 和示例 3 正常工作。

function myFunction() {
    var str1 = 'foot zi-cnn-xx vi-sky-xx test vi-axn-xx red';
    var str2 = 'foot zi-cnn vi-sky test vi-axn red';
    
    // Example 1
    // remove every '-xx'
    var res1 = str1.replace(/-xx/g, '');
    document.getElementById("demo1").innerHTML = res1;
    
    // Example 2
    // delete every '-xx' from str1 substring that starts with 'vi'
    // expected: 'foot zi-cnn-xx vi-sky test vi-axn red';
    
    // Example 3
    // add '-xx' to str2, to every substring that starts with 'vi'
    // expected: 'foot zi-cnn vi-sky-xx test vi-axn-xx red';

}

<button onclick="myFunction()">Test this</button>

<p id="demo1"></p>
<p id="demo2"></p>
<p id="demo3"></p>

Answer 1

对于情况 2，您可以将 vi-([-\w]+)-xx 替换为 vi-$1
和 vi-([-\w]+) 到案例 3 的 vi-$1-xx。

片段:

function myFunction() {
    var str1 = 'foot zi-cnn-xx vi-sky-xx test vi-axn-xx red';
    var str2 = 'foot zi-cnn vi-sky test vi-axn red';
    
    // Example 1
    // remove every '-xx'
    var res1 = str1.replace(/-xx/g, '');
    document.getElementById("demo1").innerHTML = res1;
    
    // Example 2
    // delete every '-xx' from str1 substring that starts with 'vi'
    // expected: 'foot zi-cnn-xx vi-sky test vi-axn red';
    var res2 = str1.replace(/vi-([-\w]+)-xx/g, "vi-$1");
    document.getElementById("demo2").innerHTML = res2;
    
    // Example 3
    // add '-xx' to str2, to every substring that starts with 'vi'
    // expected: 'foot zi-cnn vi-sky-xx test vi-axn-xx red';
    var res3 = str2.replace(/vi-([-\w]+)/g, "vi-$1-xx");
    document.getElementById("demo3").innerHTML = res3;

}

<button onclick="myFunction()">Test this</button>

<p id="demo1"></p>
<p id="demo2"></p>
<p id="demo3"></p>