Example:

    GTM> FOR i=0:1:3 WRITE !,$EXTRACT("HI",i),"<"
    <
    H<
    I<
    <
    GTM>
    

This loop displays the result of $EXTRACT(), specifying no ending character position and a beginning character position "before, " first and second positions, and "after" the string.

Example:

    GTM> FOR i=0:1:3 WRITE !,$E("HI",1,i),"<"
    <
    H<
    HI<
    HI<
    GTM>    
    

This loop displays the result of $EXTRACT() specifying a beginning character position of 1 and an ending character position "before, " first and second positions, and "after" the string.

Example:

    TRIM(x)
    NEW i,j
    FOR j=$L(x):-1:0 S nx=$E(x,1,j) Q:$EXTRACT(x,j)'=" "
    FOR i=1:1:j S fx=$E(nx,i,$L(x)) Q:$EXTRACT(x,i)'=" "
    QUIT fx
    GTM>SET str=" MUMPS "
    GTM>WRITE $LENGTH(str)
    7
    GTM>WRITE $LENGTH($$TRIM^trim(str))
    5    
    

This extrinsic function uses $EXTRACT() to remove extra leading and trailing spaces from its argument.