isWellFormed < String < JavaScript

The isWellFormed() of a String returns a boolean indicating whether the string contains any lone surrogates.

    
    const loneLeadingSurrogate = "ab\uD800".isWellFormed();
    console.log(loneLeadingSurrogate)
    // false

    const loneTrailingSurrogate = "\uDFFFab".isWellFormed();
    console.log(loneTrailingSurrogate)
    // false

    const wellFormed = "abc".isWellFormed();
    console.log(wellFormed)
    // true

    const wellFormed2 = "ab\uD83D\uDE04c".isWellFormed();
    console.log(wellFormed2)
    // true