在文件顶部添加 "use strict";，即可为所有代码启用严格模式：

"use strict";

function validateLicense(key) {
    // This function runs in strict mode
    return key.length === 32;
}

function processPayment(amount) {
    // This also runs in strict mode
    return amount * 1.1;
}

如果只有特定函数需要严格模式，可在这些函数内部添加 "use strict";：

/* javascript-obfuscator:vm */
function sensitiveFunction() {
    "use strict";
    // Only this function runs in strict mode
    return this === undefined; // true in strict mode
}

function regularFunction() {
    // This runs in non-strict mode
    return this; // global object
}